Merge the latest enhancements from trunk.

FossilOrigin-Name: 7bde6d4d8cf05e1beb9bdf20b85760dc3e7a76c9
2025-08-05 15:55:57 +03:00 · 2015-08-31 14:27:29 +00:00
parent 31a5d34283 3ad93bba84
commit 087f83b662
13 changed files with 596 additions and 138 deletions
--- a/Makefile.in
+++ b/Makefile.in
@@ -566,9 +566,9 @@ libtclsqlite3.la:	tclsqlite.lo libsqlite3.la
 		-version-info "8:6:8" \
 		-avoid-version

-sqlite3$(TEXE):	$(TOP)/src/shell.c libsqlite3.la sqlite3.h
-	$(LTLINK) $(READLINE_FLAGS) \
-		-o $@ $(TOP)/src/shell.c libsqlite3.la \
+sqlite3$(TEXE):	$(TOP)/src/shell.c libsqlite3.la sqlite3.h $(TOP)/ext/misc/json1.c
+	$(LTLINK) $(READLINE_FLAGS) -DSQLITE_ENABLE_JSON1 -o $@ \
+		$(TOP)/src/shell.c $(TOP)/ext/misc/json1.c libsqlite3.la \
 		$(LIBREADLINE) $(TLIBS) -rpath "$(libdir)"

 sqldiff$(TEXE):	$(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h
--- a/Makefile.msc
+++ b/Makefile.msc
@@ -390,9 +390,9 @@ CORE_LINK_OPTS = /DEF:sqlite3.def
 #
 !IFNDEF SHELL_COMPILE_OPTS
 !IF $(DYNAMIC_SHELL)!=0
-SHELL_COMPILE_OPTS = $(SHELL_CCONV_OPTS) -DSQLITE_API=__declspec(dllimport)
+SHELL_COMPILE_OPTS = -DSQLITE_ENABLE_JSON1 $(SHELL_CCONV_OPTS) -DSQLITE_API=__declspec(dllimport)
 !ELSE
-SHELL_COMPILE_OPTS = $(SHELL_CCONV_OPTS)
+SHELL_COMPILE_OPTS = -DSQLITE_ENABLE_JSON1 $(SHELL_CCONV_OPTS)
 !ENDIF
 !ENDIF

@@ -1224,8 +1224,8 @@ libsqlite3.lib:	$(LIBOBJ)
 libtclsqlite3.lib:	tclsqlite.lo libsqlite3.lib
 	$(LTLIB) $(LTLIBOPTS) $(LTLIBPATHS) /OUT:$@ tclsqlite.lo libsqlite3.lib $(LIBTCL:tcl=tclstub) $(TLIBS)

-sqlite3.exe:	$(TOP)\src\shell.c $(SHELL_CORE_DEP) $(LIBRESOBJS) sqlite3.h
-	$(LTLINK) $(SHELL_COMPILE_OPTS) $(READLINE_FLAGS) $(TOP)\src\shell.c \
+sqlite3.exe:	$(TOP)\src\shell.c $(TOP)\ext\misc\json1.c $(SHELL_CORE_DEP) $(LIBRESOBJS) sqlite3.h
+	$(LTLINK) $(SHELL_COMPILE_OPTS) $(READLINE_FLAGS) $(TOP)\src\shell.c $(TOP)\ext\misc\json1.c \
 		/link /pdb:sqlite3sh.pdb $(LTLINKOPTS) $(SHELL_LINK_OPTS) $(LTLIBPATHS) $(LIBRESOBJS) $(LIBREADLINE) $(LTLIBS) $(TLIBS)

 sqldiff.exe:	$(TOP)\tool\sqldiff.c sqlite3.c sqlite3.h
--- a/ext/misc/json1.c
+++ b/ext/misc/json1.c
@@ -21,7 +21,9 @@
 ** This implementation parses JSON text at 250 MB/s, so it is hard to see
 ** how JSONB might improve on that.)
 */
+#if !defined(_SQLITEINT_H_)
 #include "sqlite3ext.h"
+#endif
 SQLITE_EXTENSION_INIT1
 #include <assert.h>
 #include <string.h>
@@ -80,6 +82,7 @@ static const char * const jsonType[] = {
 #define JNODE_REMOVE  0x04         /* Do not output */
 #define JNODE_REPLACE 0x08         /* Replace with JsonNode.iVal */
 #define JNODE_APPEND  0x10         /* More ARRAY/OBJECT entries at u.iAppend */
+#define JNODE_JSON    0x20         /* Treat REPLACE as JSON text */


 /* A single node of parsed JSON
@@ -105,6 +108,7 @@ struct JsonParse {
  const char *zJson; /* Original JSON string */
  u32 *aUp;          /* Index of parent of each node */
  u8 oom;            /* Set to true if out of memory */
+  u8 nErr;           /* Number of errors seen */
 };

 /**************************************************************************
@@ -238,7 +242,8 @@ static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
 */
 static void jsonAppendValue(
  JsonString *p,                 /* Append to this JSON string */
-  sqlite3_value *pValue          /* Value to append */
+  sqlite3_value *pValue,         /* Value to append */
+  u8 textIsJson                  /* Try to treat text values as JSON */
 ){
  switch( sqlite3_value_type(pValue) ){
    case SQLITE_NULL: {
@@ -255,7 +260,11 @@ static void jsonAppendValue(
    case SQLITE_TEXT: {
      const char *z = (const char*)sqlite3_value_text(pValue);
      u32 n = (u32)sqlite3_value_bytes(pValue);
-      jsonAppendString(p, z, n);
+      if( textIsJson ){
+        jsonAppendRaw(p, z, n);
+      }else{
+        jsonAppendString(p, z, n);
+      }
      break;
    }
    default: {
@@ -355,7 +364,8 @@ static void jsonRenderNode(
          if( pNode[j].jnFlags & (JNODE_REMOVE|JNODE_REPLACE) ){
            if( pNode[j].jnFlags & JNODE_REPLACE ){
              jsonAppendSeparator(pOut);
-              jsonAppendValue(pOut, aReplace[pNode[j].iVal]);
+              jsonAppendValue(pOut, aReplace[pNode[j].iVal],
+                              (pNode[j].jnFlags & JNODE_JSON)!=0);
            }
          }else{
            jsonAppendSeparator(pOut);
@@ -380,7 +390,8 @@ static void jsonRenderNode(
            jsonRenderNode(&pNode[j], pOut, aReplace);
            jsonAppendChar(pOut, ':');
            if( pNode[j+1].jnFlags & JNODE_REPLACE ){
-              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal]);
+              jsonAppendValue(pOut, aReplace[pNode[j+1].iVal],
+                              (pNode[j+1].jnFlags & JNODE_JSON)!=0);
            }else{
              jsonRenderNode(&pNode[j+1], pOut, aReplace);
            }
@@ -397,6 +408,20 @@ static void jsonRenderNode(
  }
 }

+/*
+** Return a JsonNode and all its descendents as a JSON string.
+*/
+static void jsonReturnJson(
+  JsonNode *pNode,            /* Node to return */
+  sqlite3_context *pCtx,      /* Return value for this function */
+  sqlite3_value **aReplace    /* Array of replacement values */
+){
+  JsonString s;
+  jsonInit(&s, pCtx);
+  jsonRenderNode(pNode, &s, aReplace);
+  jsonResult(&s);
+}
+
 /*
 ** Make the JsonNode the return value of the function.
 */
@@ -501,10 +526,7 @@ static void jsonReturn(
    }
    case JSON_ARRAY:
    case JSON_OBJECT: {
-      JsonString s;
-      jsonInit(&s, pCtx);
-      jsonRenderNode(pNode, &s, aReplace);
-      jsonResult(&s);
+      jsonReturnJson(pNode, pCtx, aReplace);
      break;
    }
  }
@@ -668,7 +690,7 @@ static int jsonParseValue(JsonParse *pParse, u32 i){
          j++;
          c = pParse->zJson[j+1];
        }
-        if( c<'0' || c>'0' ) return -1;
+        if( c<'0' || c>'9' ) return -1;
        continue;
      }
      break;
@@ -708,8 +730,14 @@ static int jsonParse(
    while( isspace(zJson[i]) ) i++;
    if( zJson[i] ) i = -1;
  }
-  if( i<0 ){
-    if( pParse->oom && pCtx!=0 ) sqlite3_result_error_nomem(pCtx);
+  if( i<=0 ){
+    if( pCtx!=0 ){
+      if( pParse->oom ){
+        sqlite3_result_error_nomem(pCtx);
+      }else{
+        sqlite3_result_error(pCtx, "malformed JSON", -1);
+      }
+    }
    jsonParseReset(pParse);
    return 1;
  }
@@ -759,7 +787,7 @@ static int jsonParseFindParents(JsonParse *pParse){
 }

 /* forward declaration */
-static JsonNode *jsonLookupAppend(JsonParse*,const char*,int*);
+static JsonNode *jsonLookupAppend(JsonParse*,const char*,int*,const char**);

 /*
 ** Search along zPath to find the node specified.  Return a pointer
@@ -770,11 +798,12 @@ static JsonNode *jsonLookupAppend(JsonParse*,const char*,int*);
 ** possible to do so and if no existing node corresponds to zPath.  If
 ** new nodes are appended *pApnd is set to 1.
 */
-static JsonNode *jsonLookup(
+static JsonNode *jsonLookupStep(
  JsonParse *pParse,      /* The JSON to search */
  u32 iRoot,              /* Begin the search at this node */
  const char *zPath,      /* The path to search */
-  int *pApnd              /* Append nodes to complete path if not NULL */
+  int *pApnd,             /* Append nodes to complete path if not NULL */
+  const char **pzErr      /* Make *pzErr point to any syntax error in zPath */
 ){
  u32 i, j, nKey;
  const char *zKey;
@@ -793,14 +822,17 @@ static JsonNode *jsonLookup(
      for(i=0; zPath[i] && zPath[i]!='.' && zPath[i]!='['; i++){}
      nKey = i;
    }
-    if( nKey==0 ) return 0;
+    if( nKey==0 ){
+      *pzErr = zPath;
+      return 0;
+    }
    j = 1;
    for(;;){
      while( j<=pRoot->n ){
        if( pRoot[j].n==nKey+2
         && strncmp(&pRoot[j].u.zJContent[1],zKey,nKey)==0
        ){
-          return jsonLookup(pParse, iRoot+j+1, &zPath[i], pApnd);
+          return jsonLookupStep(pParse, iRoot+j+1, &zPath[i], pApnd, pzErr);
        }
        j++;
        j += jsonNodeSize(&pRoot[j]);
@@ -816,7 +848,7 @@ static JsonNode *jsonLookup(
      iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);
      iLabel = jsonParseAddNode(pParse, JSON_STRING, i, zPath);
      zPath += i;
-      pNode = jsonLookupAppend(pParse, zPath, pApnd);
+      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
      if( pParse->oom ) return 0;
      if( pNode ){
        pRoot = &pParse->aNode[iRoot];
@@ -834,7 +866,10 @@ static JsonNode *jsonLookup(
      i = i*10 + zPath[0] - '0';
      zPath++;
    }
-    if( zPath[0]!=']' ) return 0;
+    if( zPath[0]!=']' ){
+      *pzErr = zPath;
+      return 0;
+    }
    zPath++;
    j = 1;
    for(;;){
@@ -848,13 +883,13 @@ static JsonNode *jsonLookup(
      j = 1;
    }
    if( j<=pRoot->n ){
-      return jsonLookup(pParse, iRoot+j, zPath, pApnd);
+      return jsonLookupStep(pParse, iRoot+j, zPath, pApnd, pzErr);
    }
    if( i==0 && pApnd ){
      u32 iStart;
      JsonNode *pNode;
      iStart = jsonParseAddNode(pParse, JSON_ARRAY, 1, 0);
-      pNode = jsonLookupAppend(pParse, zPath, pApnd);
+      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
      if( pParse->oom ) return 0;
      if( pNode ){
        pRoot = &pParse->aNode[iRoot];
@@ -863,6 +898,8 @@ static JsonNode *jsonLookup(
      }
      return pNode;
    }
+  }else if( zPath[0]!=0 ){
+    *pzErr = zPath;
  }
  return 0;
 }
@@ -874,7 +911,8 @@ static JsonNode *jsonLookup(
 static JsonNode *jsonLookupAppend(
  JsonParse *pParse,     /* Append content to the JSON parse */
  const char *zPath,     /* Description of content to append */
-  int *pApnd             /* Set this flag to 1 */
+  int *pApnd,            /* Set this flag to 1 */
+  const char **pzErr     /* Make this point to any syntax error */
 ){
  *pApnd = 1;
  if( zPath[0]==0 ){
@@ -889,9 +927,76 @@ static JsonNode *jsonLookupAppend(
    return 0;
  }
  if( pParse->oom ) return 0;
-  return jsonLookup(pParse, pParse->nNode-1, zPath, pApnd);
+  return jsonLookupStep(pParse, pParse->nNode-1, zPath, pApnd, pzErr);
 }

+/*
+** Return the text of a syntax error message on a JSON path.  Space is
+** obtained from sqlite3_malloc().
+*/
+static char *jsonPathSyntaxError(const char *zErr){
+  return sqlite3_mprintf("JSON path error near '%q'", zErr);
+}
+
+/*
+** Do a node lookup using zPath.  Return a pointer to the node on success.
+** Return NULL if not found or if there is an error.
+**
+** On an error, write an error message into pCtx and increment the
+** pParse->nErr counter.
+**
+** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if
+** nodes are appended.
+**
+** If the path starts with $$ then set *pFlags to JNODE_REPLACE|JNODE_JSON
+** as a single to the caller that the input text to be inserted should be 
+** interpreted as JSON rather than as ordinary text.
+*/
+static JsonNode *jsonLookup(
+  JsonParse *pParse,      /* The JSON to search */
+  const char *zPath,      /* The path to search */
+  int *pApnd,             /* Append nodes to complete path if not NULL */
+  sqlite3_context *pCtx,  /* Report errors here, if not NULL */
+  u8 *pFlags              /* Write JNODE_REPLACE or _REPLACE|_JSON here */
+){
+  const char *zErr = 0;
+  JsonNode *pNode = 0;
+  u8 fg = JNODE_REPLACE;
+
+  if( zPath==0 ) return 0;
+  if( zPath[0]!='$' ){
+    zErr = zPath;
+    goto lookup_err;
+  }
+  zPath++;
+  if( zPath[0]=='$' ){
+    if( pFlags==0 ){
+      zErr = zPath;
+      goto lookup_err;
+    }
+    zPath++;
+    fg = JNODE_REPLACE|JNODE_JSON;
+  }
+  if( pFlags ) *pFlags = fg;
+  pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);
+  return pNode;
+
+lookup_err:
+  pParse->nErr++;
+  if( zErr!=0 && pCtx!=0 ){
+    char *z = jsonPathSyntaxError(zErr);
+    if( z ){
+      sqlite3_result_error(pCtx, z, -1);
+      sqlite3_free(z);
+    }else{
+      sqlite3_result_error_nomem(pCtx);
+    }
+  }
+  if( pFlags ) *pFlags = fg;
+  return 0;
+}
+
+
 /*
 ** Report the wrong number of arguments for json_insert(), json_replace()
 ** or json_set().
@@ -906,6 +1011,7 @@ static void jsonWrongNumArgs(
  sqlite3_free(zMsg);     
 }

+
 /****************************************************************************
 ** SQL functions used for testing and debugging
 ****************************************************************************/
@@ -952,7 +1058,7 @@ static void jsonTest1Func(
 ){
  JsonParse x;  /* The parse */
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
-  jsonReturn(x.aNode, ctx, 0);
+  jsonReturnJson(x.aNode, ctx, 0);
  jsonParseReset(&x);
 }

@@ -993,7 +1099,7 @@ static void jsonArrayFunc(
  jsonAppendChar(&jx, '[');
  for(i=0; i<argc; i++){
    jsonAppendSeparator(&jx);
-    jsonAppendValue(&jx, argv[i]);
+    jsonAppendValue(&jx, argv[i], 0);
  }
  jsonAppendChar(&jx, ']');
  jsonResult(&jx);
@@ -1015,37 +1121,36 @@ static void jsonArrayLengthFunc(
  JsonParse x;          /* The parse */
  sqlite3_int64 n = 0;
  u32 i;
-  const char *zPath;

-  if( argc==2 ){
-    zPath = (const char*)sqlite3_value_text(argv[1]);
-    if( zPath==0 ) return;
-    if( zPath[0]!='$' ) return;
-    zPath++;
-  }else{
-    zPath = 0;
-  }
-  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0]))==0 ){
-    if( x.nNode ){
-      JsonNode *pNode = x.aNode;
-      if( zPath ) pNode = jsonLookup(&x, 0, zPath, 0);
-      if( pNode->eType==JSON_ARRAY ){
-        assert( (pNode->jnFlags & JNODE_APPEND)==0 );
-        for(i=1; i<=pNode->n; n++){
-          i += jsonNodeSize(&pNode[i]);
-        }
+  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
+  if( x.nNode ){
+    JsonNode *pNode;
+    if( argc==2 ){
+      const char *zPath = (const char*)sqlite3_value_text(argv[1]);
+      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+    }else{
+      pNode = x.aNode;
+    }
+    if( pNode==0 ){
+      x.nErr = 1;
+    }else if( pNode->eType==JSON_ARRAY ){
+      assert( (pNode->jnFlags & JNODE_APPEND)==0 );
+      for(i=1; i<=pNode->n; n++){
+        i += jsonNodeSize(&pNode[i]);
      }
    }
-    jsonParseReset(&x);
  }
-  if( !x.oom ) sqlite3_result_int64(ctx, n);
+  if( x.nErr==0 ) sqlite3_result_int64(ctx, n);
+  jsonParseReset(&x);
 }

 /*
-** json_extract(JSON, PATH)
+** json_extract(JSON, PATH, ...)
 **
-** Return the element described by PATH.  Return NULL if JSON is not
-** valid JSON or if there is no PATH element or if PATH is malformed.
+** Return the element described by PATH.  Return NULL if there is no
+** PATH element.  If there are multiple PATHs, then return a JSON array
+** with the result from each path.  Throw an error if the JSON or any PATH
+** is malformed.
 */
 static void jsonExtractFunc(
  sqlite3_context *ctx,
@@ -1055,16 +1160,33 @@ static void jsonExtractFunc(
  JsonParse x;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
-  assert( argc==2 );
-  zPath = (const char*)sqlite3_value_text(argv[1]);
-  if( zPath==0 ) return;
-  if( zPath[0]!='$' ) return;
-  zPath++;
+  JsonString jx;
+  int i;
+
+  if( argc<2 ) return;
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
-  pNode = jsonLookup(&x, 0, zPath, 0);
-  if( pNode ){
-    jsonReturn(pNode, ctx, 0);
+  jsonInit(&jx, ctx);
+  jsonAppendChar(&jx, '[');
+  for(i=1; i<argc; i++){
+    zPath = (const char*)sqlite3_value_text(argv[i]);
+    pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+    if( x.nErr ) break;
+    if( argc>2 ){
+      jsonAppendSeparator(&jx);
+      if( pNode ){
+        jsonRenderNode(pNode, &jx, 0);
+      }else{
+        jsonAppendRaw(&jx, "null", 4);
+      }
+    }else if( pNode ){
+      jsonReturn(pNode, ctx, 0);
+    }
  }
+  if( argc>2 && i==argc ){
+    jsonAppendChar(&jx, ']');
+    jsonResult(&jx);
+  }
+  jsonReset(&jx);
  jsonParseReset(&x);
 }

@@ -1101,7 +1223,7 @@ static void jsonObjectFunc(
    n = (u32)sqlite3_value_bytes(argv[i]);
    jsonAppendString(&jx, z, n);
    jsonAppendChar(&jx, ':');
-    jsonAppendValue(&jx, argv[i+1]);
+    jsonAppendValue(&jx, argv[i+1], 0);
  }
  jsonAppendChar(&jx, '}');
  jsonResult(&jx);
@@ -1111,9 +1233,8 @@ static void jsonObjectFunc(
 /*
 ** json_remove(JSON, PATH, ...)
 **
-** Remove the named elements from JSON and return the result.  Ill-formed
-** PATH arguments are silently ignored.  If JSON is ill-formed, then NULL
-** is returned.
+** Remove the named elements from JSON and return the result.  malformed
+** JSON or PATH arguments result in an error.
 */
 static void jsonRemoveFunc(
  sqlite3_context *ctx,
@@ -1130,15 +1251,16 @@ static void jsonRemoveFunc(
  if( x.nNode ){
    for(i=1; i<(u32)argc; i++){
      zPath = (const char*)sqlite3_value_text(argv[i]);
-      if( zPath==0 ) continue;
-      if( zPath[0]!='$' ) continue;
-      pNode = jsonLookup(&x, 0, &zPath[1], 0);
+      if( zPath==0 ) goto remove_done;
+      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+      if( x.nErr ) goto remove_done;
      if( pNode ) pNode->jnFlags |= JNODE_REMOVE;
    }
    if( (x.aNode[0].jnFlags & JNODE_REMOVE)==0 ){
-      jsonReturn(x.aNode, ctx, 0);
+      jsonReturnJson(x.aNode, ctx, 0);
    }
  }
+remove_done:
  jsonParseReset(&x);
 }

@@ -1146,7 +1268,7 @@ static void jsonRemoveFunc(
 ** json_replace(JSON, PATH, VALUE, ...)
 **
 ** Replace the value at PATH with VALUE.  If PATH does not already exist,
-** this routine is a no-op.  If JSON is ill-formed, return NULL.
+** this routine is a no-op.  If JSON or PATH is malformed, throw an error.
 */
 static void jsonReplaceFunc(
  sqlite3_context *ctx,
@@ -1166,21 +1288,23 @@ static void jsonReplaceFunc(
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i+=2){
+      u8 jnFlags = JNODE_REPLACE;
      zPath = (const char*)sqlite3_value_text(argv[i]);
-      if( zPath==0 ) continue;
-      if( zPath[0]!='$' ) continue;
-      pNode = jsonLookup(&x, 0, &zPath[1], 0);
+      pNode = jsonLookup(&x, zPath, 0, ctx, &jnFlags);
+      if( x.nErr ) goto replace_err;
      if( pNode ){
-        pNode->jnFlags |= JNODE_REPLACE;
+        pNode->jnFlags &= ~JNODE_JSON;
+        pNode->jnFlags |= jnFlags;
        pNode->iVal = i+1;
      }
    }
    if( x.aNode[0].jnFlags & JNODE_REPLACE ){
      sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
    }else{
-      jsonReturn(x.aNode, ctx, argv);
+      jsonReturnJson(x.aNode, ctx, argv);
    }
  }
+replace_err:
  jsonParseReset(&x);
 }

@@ -1189,12 +1313,12 @@ static void jsonReplaceFunc(
 **
 ** Set the value at PATH to VALUE.  Create the PATH if it does not already
 ** exist.  Overwrite existing values that do exist.
-** If JSON is ill-formed, return NULL.
+** If JSON or PATH is malformed, throw an error.
 **
 ** json_insert(JSON, PATH, VALUE, ...)
 **
 ** Create PATH and initialize it to VALUE.  If PATH already exists, this
-** routine is a no-op.  If JSON is ill-formed, return NULL.
+** routine is a no-op.  If JSON or PATH is malformed, throw an error.
 */
 static void jsonSetFunc(
  sqlite3_context *ctx,
@@ -1216,23 +1340,25 @@ static void jsonSetFunc(
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
    for(i=1; i<(u32)argc; i+=2){
+      u8 jnFlags = JNODE_REPLACE;
      zPath = (const char*)sqlite3_value_text(argv[i]);
-      if( zPath==0 ) continue;
-      if( zPath[0]!='$' ) continue;
      bApnd = 0;
-      pNode = jsonLookup(&x, 0, &zPath[1], &bApnd);
+      pNode = jsonLookup(&x, zPath, &bApnd, ctx, &jnFlags);
      if( x.oom ){
        sqlite3_result_error_nomem(ctx);
        goto jsonSetDone;
+      }else if( x.nErr ){
+        goto jsonSetDone;
      }else if( pNode && (bApnd || bIsSet) ){
-        pNode->jnFlags |= JNODE_REPLACE;
+        pNode->jnFlags &= ~JNODE_JSON;
+        pNode->jnFlags |= jnFlags;
        pNode->iVal = i+1;
      }
    }
    if( x.aNode[0].jnFlags & JNODE_REPLACE ){
      sqlite3_result_value(ctx, argv[x.aNode[0].iVal]);
    }else{
-      jsonReturn(x.aNode, ctx, argv);
+      jsonReturnJson(x.aNode, ctx, argv);
    }
  }
 jsonSetDone:
@@ -1243,8 +1369,8 @@ jsonSetDone:
 ** json_type(JSON)
 ** json_type(JSON, PATH)
 **
-** Return the top-level "type" of a JSON string.  Return NULL if the
-** input is not a well-formed JSON string.
+** Return the top-level "type" of a JSON string.  Throw an error if
+** either the JSON or PATH inputs are not well-formed.
 */
 static void jsonTypeFunc(
  sqlite3_context *ctx,
@@ -1254,18 +1380,15 @@ static void jsonTypeFunc(
  JsonParse x;          /* The parse */
  const char *zPath;

-  if( argc==2 ){
-    zPath = (const char*)sqlite3_value_text(argv[1]);
-    if( zPath==0 ) return;
-    if( zPath[0]!='$' ) return;
-    zPath++;
-  }else{
-    zPath = 0;
-  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( x.nNode ){
-    JsonNode *pNode = x.aNode;
-    if( zPath ) pNode = jsonLookup(&x, 0, zPath, 0);
+    JsonNode *pNode;
+    if( argc==2 ){
+      zPath = (const char*)sqlite3_value_text(argv[1]);
+      pNode = jsonLookup(&x, zPath, 0, ctx, 0);
+    }else{
+      pNode = x.aNode;
+    }
    if( pNode ){
      sqlite3_result_text(ctx, jsonType[pNode->eType], -1, SQLITE_STATIC);
    }
@@ -1276,7 +1399,8 @@ static void jsonTypeFunc(
 /*
 ** json_valid(JSON)
 **
-** Return 1 if JSON is a valid JSON string.  Return 0 otherwise.
+** Return 1 if JSON is a well-formed JSON string according to RFC-7159.
+** Return 0 otherwise.
 */
 static void jsonValidFunc(
  sqlite3_context *ctx,
@@ -1286,7 +1410,7 @@ static void jsonValidFunc(
  JsonParse x;          /* The parse */
  int rc = 0;

-  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0]))==0 
+  if( jsonParse(&x, 0, (const char*)sqlite3_value_text(argv[0]))==0 
   && x.nNode>0
  ){
    rc = 1;
@@ -1295,6 +1419,7 @@ static void jsonValidFunc(
  sqlite3_result_int(ctx, rc);
 }

+#ifndef SQLITE_OMIT_VIRTUALTABLE
 /****************************************************************************
 ** The json_each virtual table
 ****************************************************************************/
@@ -1642,27 +1767,45 @@ static int jsonEachFilter(
  if( z==0 ) return SQLITE_OK;
  if( idxNum&2 ){
    zPath = (const char*)sqlite3_value_text(argv[1]);
-    if( zPath==0 || zPath[0]!='$' ) return SQLITE_OK;
+    if( zPath==0 ) return SQLITE_OK;
+    if( zPath[0]!='$' ){
+      sqlite3_free(cur->pVtab->zErrMsg);
+      cur->pVtab->zErrMsg = jsonPathSyntaxError(zPath);
+      return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
+    }
  }
  n = sqlite3_value_bytes(argv[0]);
  p->zJson = sqlite3_malloc64( n+1 );
  if( p->zJson==0 ) return SQLITE_NOMEM;
  memcpy(p->zJson, z, (size_t)n+1);
-  if( jsonParse(&p->sParse, 0, p->zJson) 
-   || (p->bRecursive && jsonParseFindParents(&p->sParse))
-  ){
+  if( jsonParse(&p->sParse, 0, p->zJson) ){
+    int rc = SQLITE_NOMEM;
+    if( p->sParse.oom==0 ){
+      sqlite3_free(cur->pVtab->zErrMsg);
+      cur->pVtab->zErrMsg = sqlite3_mprintf("malformed JSON");
+      if( cur->pVtab->zErrMsg ) rc = SQLITE_ERROR;
+    }
    jsonEachCursorReset(p);
+    return rc;
+  }else if( p->bRecursive && jsonParseFindParents(&p->sParse) ){
+    jsonEachCursorReset(p);
+    return SQLITE_NOMEM;
  }else{
    JsonNode *pNode;
    if( idxNum==3 ){
+      const char *zErr = 0;
      p->bRecursive = 0;
      n = sqlite3_value_bytes(argv[1]);
      p->zPath = sqlite3_malloc64( n+1 );
      if( p->zPath==0 ) return SQLITE_NOMEM;
      memcpy(p->zPath, zPath, (size_t)n+1);
-      pNode = jsonLookup(&p->sParse, 0, p->zPath+1, 0);
-      if( pNode==0 ){
+      pNode = jsonLookupStep(&p->sParse, 0, p->zPath+1, 0, &zErr);
+      if( p->sParse.nErr ){
+        sqlite3_free(cur->pVtab->zErrMsg);
+        cur->pVtab->zErrMsg = jsonPathSyntaxError(zErr);
        jsonEachCursorReset(p);
+        return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
+      }else if( pNode==0 ){
        return SQLITE_OK;
      }
    }else{
@@ -1734,6 +1877,7 @@ static sqlite3_module jsonTreeModule = {
  0,                         /* xRelease */
  0                          /* xRollbackTo */
 };
+#endif /* SQLITE_OMIT_VIRTUALTABLE */

 /****************************************************************************
 ** The following routine is the only publically visible identifier in this
@@ -1760,7 +1904,7 @@ int sqlite3_json_init(
    { "json_array",          -1, 0,   jsonArrayFunc         },
    { "json_array_length",    1, 0,   jsonArrayLengthFunc   },
    { "json_array_length",    2, 0,   jsonArrayLengthFunc   },
-    { "json_extract",         2, 0,   jsonExtractFunc       },
+    { "json_extract",        -1, 0,   jsonExtractFunc       },
    { "json_insert",         -1, 0,   jsonSetFunc           },
    { "json_object",         -1, 0,   jsonObjectFunc        },
    { "json_remove",         -1, 0,   jsonRemoveFunc        },
@@ -1777,6 +1921,7 @@ int sqlite3_json_init(
    { "json_nodecount",       1, 0,   jsonNodeCountFunc     },
 #endif
  };
+#ifndef SQLITE_OMIT_VIRTUALTABLE
  static const struct {
     const char *zName;
     sqlite3_module *pModule;
@@ -1784,6 +1929,7 @@ int sqlite3_json_init(
    { "json_each",            &jsonEachModule               },
    { "json_tree",            &jsonTreeModule               },
  };
+#endif
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
@@ -1792,8 +1938,10 @@ int sqlite3_json_init(
                                 (void*)&aFunc[i].flag,
                                 aFunc[i].xFunc, 0, 0);
  }
+#ifndef SQLITE_OMIT_VIRTUALTABLE
  for(i=0; i<sizeof(aMod)/sizeof(aMod[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_module(db, aMod[i].zName, aMod[i].pModule, 0);
  }
+#endif
  return rc;
 }
--- a/ext/rbu/sqlite3rbu.c
+++ b/ext/rbu/sqlite3rbu.c
@@ -489,7 +489,7 @@ static int rbuDeltaApply(
          /* ERROR: copy exceeds output file size */
          return -1;
        }
-        if( ofst+cnt > lenSrc ){
+        if( (int)(ofst+cnt) > lenSrc ){
          /* ERROR: copy extends past end of input */
          return -1;
        }
@@ -504,7 +504,7 @@ static int rbuDeltaApply(
          /* ERROR:  insert command gives an output larger than predicted */
          return -1;
        }
-        if( cnt>lenDelta ){
+        if( (int)cnt>lenDelta ){
          /* ERROR: insert count exceeds size of delta */
          return -1;
        }
@@ -1117,7 +1117,7 @@ static void rbuTableType(
  }

 rbuTableType_end: {
-    int i;
+    unsigned int i;
    for(i=0; i<sizeof(aStmt)/sizeof(aStmt[0]); i++){
      rbuFinalize(p, aStmt[i]);
    }
@@ -1530,7 +1530,7 @@ static char *rbuObjIterGetSetlist(
  if( p->rc==SQLITE_OK ){
    int i;

-    if( strlen(zMask)!=pIter->nTblCol ){
+    if( (int)strlen(zMask)!=pIter->nTblCol ){
      rbuBadControlError(p);
    }else{
      const char *zSep = "";
@@ -3680,7 +3680,8 @@ static int rbuVfsOpen(
    rbuVfsShmMap,                 /* xShmMap */
    rbuVfsShmLock,                /* xShmLock */
    rbuVfsShmBarrier,             /* xShmBarrier */
-    rbuVfsShmUnmap                /* xShmUnmap */
+    rbuVfsShmUnmap,               /* xShmUnmap */
+    0, 0                          /* xFetch, xUnfetch */
  };
  rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs;
  sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs;
--- a/main.mk
+++ b/main.mk
@@ -439,9 +439,9 @@ libsqlite3.a:	$(LIBOBJ)
 	$(AR) libsqlite3.a $(LIBOBJ)
 	$(RANLIB) libsqlite3.a

-sqlite3$(EXE):	$(TOP)/src/shell.c libsqlite3.a sqlite3.h
-	$(TCCX) $(READLINE_FLAGS) -o sqlite3$(EXE)                  \
-		$(TOP)/src/shell.c                                  \
+sqlite3$(EXE):	$(TOP)/src/shell.c libsqlite3.a sqlite3.h $(TOP)/ext/misc/json1.c
+	$(TCCX) $(READLINE_FLAGS) -DSQLITE_ENABLE_JSON1 -o sqlite3$(EXE)  \
+		$(TOP)/src/shell.c $(TOP)/ext/misc/json1.c                \
 		libsqlite3.a $(LIBREADLINE) $(TLIBS) $(THREADLIB)

 sqldiff$(EXE):	$(TOP)/tool/sqldiff.c sqlite3.c sqlite3.h
--- a/32
+++ b/32
@@ -1,9 +1,9 @@
-C Fix\sthe\sOR-optimization\sso\sthat\sit\salways\signores\ssubplans\sthat\sdo\snot\suse\san\sindex.
-D 2015-08-27T23:42:43.629
+C Merge\sthe\slatest\senhancements\sfrom\strunk.
+D 2015-08-31T14:27:29.928
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
-F Makefile.in e2218eb228374422969de7b1680eda6864affcef
+F Makefile.in f85066ce844a28b671aaeeff320921cd0ce36239
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
-F Makefile.msc 10af19cc089862481d49b347acd99c02635ddc49
+F Makefile.msc b268d8be2e800b9d35f074b1ed6b2f698deebdd6
 F Makefile.vxworks e1b65dea203f054e71653415bd8f96dcaed47858
 F README.md 8ecc12493ff9f820cdea6520a9016001cb2e59b7
 F VERSION ccfc4d1576dbfdeece0a4372a2e6a2e37d3e7975
@@ -192,7 +192,7 @@ F ext/misc/eval.c f971962e92ebb8b0a4e6b62949463ee454d88fa2
 F ext/misc/fileio.c d4171c815d6543a9edef8308aab2951413cd8d0f
 F ext/misc/fuzzer.c 4c84635c71c26cfa7c2e5848cf49fe2d2cfcd767
 F ext/misc/ieee754.c b0362167289170627659e84173f5d2e8fee8566e
-F ext/misc/json1.c 541004e47235cefc2843ab03c100517452931913
+F ext/misc/json1.c bd51e8c1e8ce580e6f21493bd8e94ed5aca3d777
 F ext/misc/nextchar.c 35c8b8baacb96d92abbb34a83a997b797075b342
 F ext/misc/percentile.c bcbee3c061b884eccb80e21651daaae8e1e43c63
 F ext/misc/regexp.c af92cdaa5058fcec1451e49becc7ba44dba023dc
@@ -226,7 +226,7 @@ F ext/rbu/rbufault.test cc0be8d5d392d98b0c2d6a51be377ea989250a89
 F ext/rbu/rbufault2.test 9a7f19edd6ea35c4c9f807d8a3db0a03a5670c06
 F ext/rbu/rbufts.test 828cd689da825f0a7b7c53ffc1f6f7fdb6fa5bda
 F ext/rbu/rbusave.test 0f43b6686084f426ddd040b878426452fd2c2f48
-F ext/rbu/sqlite3rbu.c 1650e682b3568db0ed97ff2c7ba5d1c8ea060a84
+F ext/rbu/sqlite3rbu.c 4ba82bd850aa012f73c31dd242d570f18c9cc35a
 F ext/rbu/sqlite3rbu.h 5357f070cd8c0bcad459b620651ec1656859e4d0
 F ext/rbu/test_rbu.c 2a3652241fa45d5eaa141775e4ae68c1d3582c03
 F ext/rtree/README 6315c0d73ebf0ec40dedb5aa0e942bc8b54e3761
@@ -258,7 +258,7 @@ F ext/userauth/userauth.c 5fa3bdb492f481bbc1709fc83c91ebd13460c69e
 F install-sh 9d4de14ab9fb0facae2f48780b874848cbf2f895 x
 F ltmain.sh 3ff0879076df340d2e23ae905484d8c15d5fdea8
 F magic.txt 8273bf49ba3b0c8559cb2774495390c31fd61c60
-F main.mk 04840e8277ab5159af16172eafd214dae7cffff5
+F main.mk 8da13ed011a7ae19450b7554910ff4afa3bd22b7
 F mkopcodec.awk c2ff431854d702cdd2d779c9c0d1f58fa16fa4ea
 F mkopcodeh.awk 0e7f04a8eb90f92259e47d80110e4e98d7ce337a
 F mkso.sh fd21c06b063bb16a5d25deea1752c2da6ac3ed83
@@ -282,7 +282,7 @@ F src/btmutex.c 45a968cc85afed9b5e6cf55bf1f42f8d18107f79
 F src/btree.c f48b3ef91676c06a90a8832987ecef6b94c931ee
 F src/btree.h 969adc948e89e449220ff0ff724c94bb2a52e9f1
 F src/btreeInt.h 8177c9ab90d772d6d2c6c517e05bed774b7c92c0
-F src/build.c 6b7f6ccacd9cbd113f1948b4268cb81a87ee513a
+F src/build.c e0902658fc86dbd60a5c6772ca45429c69ee81fe
 F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
 F src/complete.c addcd8160b081131005d5bc2d34adf20c1c5c92f
 F src/ctime.c 5a0b735dc95604766f5dac73973658eef782ee8b
@@ -338,7 +338,7 @@ F src/random.c ba2679f80ec82c4190062d756f22d0c358180696
 F src/resolve.c e6dc5a5490cf93afc1cc2cb58280c98da56acb3c
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
 F src/select.c b52c80f2b1bdb62491f9ce40eea0c5f80c78d105
-F src/shell.c 5a08835e85c502978bde35a89d4045833f772876
+F src/shell.c 6332ef06db1390ef812cfdff1fc97b4fd76cdd42
 F src/sqlite.h.in 378bebc8fe6a88bade25e5f23b7e6123fdc64b00
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h f700e6a9dd1fdcccc9951ab022b366fb66b9e413
@@ -411,7 +411,7 @@ F src/vdbesort.c f5009e7a35e3065635d8918b9a31f498a499976b
 F src/vdbetrace.c 8befe829faff6d9e6f6e4dee5a7d3f85cc85f1a0
 F src/vtab.c d31174e4c8f592febab3fa7f69e18320b4fd657a
 F src/vxworks.h c18586c8edc1bddbc15c004fa16aeb1e1342b4fb
-F src/wal.c 6fb6b68969e4692593c2552c4e7bff5882de2cb8
+F src/wal.c 8cd07f1f99e1a81346db1c9da879bef6c6f97cf6
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 2e14d17f592d176b6dc879c33fbdec4fbccaa2ba
 F src/where.c acec45dc602a4f58e80e6fa088b9379ccfffd3a4
@@ -810,7 +810,7 @@ F test/journal3.test ff8af941f9e06161d3db1b46bb9f965ff0e7f307
 F test/jrnlmode.test 7864d59cf7f6e552b9b99ba0f38acd167edc10fa
 F test/jrnlmode2.test 81610545a4e6ed239ea8fa661891893385e23a1d
 F test/jrnlmode3.test 556b447a05be0e0963f4311e95ab1632b11c9eaa
-F test/json101.test 950ed4e8deb8ad4c10bd4fbc858eb54143de9867
+F test/json101.test 11535d8986184500f4c30cc2f0b154b4ab05cc4e
 F test/keyword1.test 37ef6bba5d2ed5b07ecdd6810571de2956599dff
 F test/lastinsert.test 42e948fd6442f07d60acbd15d33fb86473e0ef63
 F test/laststmtchanges.test ae613f53819206b3222771828d024154d51db200
@@ -942,7 +942,7 @@ F test/rollback2.test fc14cf6d1a2b250d2735ef16124b971bce152f14
 F test/rollbackfault.test 6a004f71087cc399296cffbb5429ea6da655ae65
 F test/rowallock.test 3f88ec6819489d0b2341c7a7528ae17c053ab7cc
 F test/rowhash.test 0bc1d31415e4575d10cacf31e1a66b5cc0f8be81
-F test/rowid.test 09fcded0c96fbc0ed11fb75faa3b0bad32cb011a
+F test/rowid.test 5b7509f384f4f6fae1af3c8c104c8ca299fea18d
 F test/rtree.test 0c8d9dd458d6824e59683c19ab2ffa9ef946f798
 F test/run-wordcount.sh 891e89c4c2d16e629cd45951d4ed899ad12afc09
 F test/savepoint.test c671fdbd34cd3bfe1518a777526ada595180cf8d
@@ -1264,7 +1264,7 @@ F test/wal2.test 1f841d2048080d32f552942e333fd99ce541dada
 F test/wal3.test 2b5445e5da44780b9b44712f5a38523f7aeb0941
 F test/wal4.test 4744e155cd6299c6bd99d3eab1c82f77db9cdb3c
 F test/wal5.test 88b5d9a6a3d1532497ee9f4296f010d66f07e33c
-F test/wal6.test 527581f5527bf9c24394991e2be83000aace5f9e
+F test/wal6.test 4421cd5a2fa99d29cc91ef12fb23bed171ed3a4c
 F test/wal64k.test 163655ecd2cb8afef4737cac2a40fdd2eeaf20b8
 F test/wal7.test 2ae8f427d240099cc4b2dfef63cff44e2a68a1bd
 F test/wal8.test 75c42e1bc4545c277fed212f8fc9b7723cd02216
@@ -1380,7 +1380,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 73d361ce9e4d72c943def8b0b3caa227f9199aed 66f92a16866e5825363636b9cc4b8f9b29d9e84d
-R b576dddb4c7e794820789b114785ae51
+P cf452028d1be2c5578a07f6e21b4d8b613373eb8 1da60c3dda4254620052a83c853c2d2b6dd5009f
+R 64522485917d5b93eb19dc63143d2895
 U drh
-Z e54726d52fd301793beed6904550b28b
+Z 590b51e0f03c976eccd82950be2fb3fc
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-cf452028d1be2c5578a07f6e21b4d8b613373eb8
+7bde6d4d8cf05e1beb9bdf20b85760dc3e7a76c9
--- a/src/build.c
+++ b/src/build.c
@@ -356,7 +356,7 @@ Table *sqlite3LocateTable(
  p = sqlite3FindTable(pParse->db, zName, zDbase);
  if( p==0 ){
    const char *zMsg = isView ? "no such view" : "no such table";
-#ifndef SQLITE_OMIT_VIRTUAL_TABLE
+#ifndef SQLITE_OMIT_VIRTUALTABLE
    /* If zName is the not the name of a table in the schema created using
    ** CREATE, then check to see if it is the name of an virtual table that
    ** can be an eponymous virtual table. */
--- a/src/shell.c
+++ b/src/shell.c
@@ -4619,6 +4619,13 @@ int SQLITE_CDECL main(int argc, char **argv){
  }
  data.out = stdout;

+#ifdef SQLITE_ENABLE_JSON1
+  {
+    extern int sqlite3_json_init(sqlite3*);
+    sqlite3_auto_extension((void(*)(void))sqlite3_json_init);
+  }
+#endif
+
  /* Go ahead and open the database file if it already exists.  If the
  ** file does not exist, delay opening it.  This prevents empty database
  ** files from being created if a user mistypes the database name argument
--- a/src/wal.c
+++ b/src/wal.c
@@ -428,6 +428,7 @@ struct Wal {
  u8 syncHeader;             /* Fsync the WAL header if true */
  u8 padToSectorBoundary;    /* Pad transactions out to the next sector */
  WalIndexHdr hdr;           /* Wal-index header for current transaction */
+  u32 minFrame;              /* Ignore wal frames before this one */
  const char *zWalName;      /* Name of WAL file */
  u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
 #ifdef SQLITE_DEBUG
@@ -2296,12 +2297,27 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
    ** pWal->hdr.mxFrame risks reading a corrupted snapshot. So, retry
    ** instead.
    **
-    ** This does not guarantee that the copy of the wal-index header is up to
-    ** date before proceeding. That would not be possible without somehow
-    ** blocking writers. It only guarantees that a dangerous checkpoint or 
-    ** log-wrap (either of which would require an exclusive lock on
-    ** WAL_READ_LOCK(mxI)) has not occurred since the snapshot was valid.
+    ** Before checking that the live wal-index header has not changed
+    ** since it was read, set Wal.minFrame to the first frame in the wal
+    ** file that has not yet been checkpointed. This client will not need
+    ** to read any frames earlier than minFrame from the wal file - they
+    ** can be safely read directly from the database file.
+    **
+    ** Because a ShmBarrier() call is made between taking the copy of 
+    ** nBackfill and checking that the wal-header in shared-memory still
+    ** matches the one cached in pWal->hdr, it is guaranteed that the 
+    ** checkpointer that set nBackfill was not working with a wal-index
+    ** header newer than that cached in pWal->hdr. If it were, that could
+    ** cause a problem. The checkpointer could omit to checkpoint
+    ** a version of page X that lies before pWal->minFrame (call that version
+    ** A) on the basis that there is a newer version (version B) of the same
+    ** page later in the wal file. But if version B happens to like past
+    ** frame pWal->hdr.mxFrame - then the client would incorrectly assume
+    ** that it can read version A from the database file. However, since
+    ** we can guarantee that the checkpointer that set nBackfill could not
+    ** see any pages past pWal->hdr.mxFrame, this problem does not come up.
    */
+    pWal->minFrame = pInfo->nBackfill+1;
    walShmBarrier(pWal);
    if( pInfo->aReadMark[mxI]!=mxReadMark
     || memcmp((void *)walIndexHdr(pWal), &pWal->hdr, sizeof(WalIndexHdr))
@@ -2372,6 +2388,7 @@ int sqlite3WalFindFrame(
  u32 iRead = 0;                  /* If !=0, WAL frame to return data from */
  u32 iLast = pWal->hdr.mxFrame;  /* Last page in WAL for this reader */
  int iHash;                      /* Used to loop through N hash tables */
+  int iMinHash;

  /* This routine is only be called from within a read transaction. */
  assert( pWal->readLock>=0 || pWal->lockError );
@@ -2412,7 +2429,8 @@ int sqlite3WalFindFrame(
  **     This condition filters out entries that were added to the hash
  **     table after the current read-transaction had started.
  */
-  for(iHash=walFramePage(iLast); iHash>=0 && iRead==0; iHash--){
+  iMinHash = walFramePage(pWal->minFrame);
+  for(iHash=walFramePage(iLast); iHash>=iMinHash && iRead==0; iHash--){
    volatile ht_slot *aHash;      /* Pointer to hash table */
    volatile u32 *aPgno;          /* Pointer to array of page numbers */
    u32 iZero;                    /* Frame number corresponding to aPgno[0] */
@@ -2427,7 +2445,7 @@ int sqlite3WalFindFrame(
    nCollide = HASHTABLE_NSLOT;
    for(iKey=walHash(pgno); aHash[iKey]; iKey=walNextHash(iKey)){
      u32 iFrame = aHash[iKey] + iZero;
-      if( iFrame<=iLast && aPgno[aHash[iKey]]==pgno ){
+      if( iFrame<=iLast && iFrame>=pWal->minFrame && aPgno[aHash[iKey]]==pgno ){
        assert( iFrame>iRead || CORRUPT_DB );
        iRead = iFrame;
      }
--- a/test/json101.test
+++ b/test/json101.test
@@ -50,5 +50,246 @@ do_catchsql_test json1-2.4 {
  SELECT json_object('a',1,'b',x'abcd');
 } {1 {JSON cannot hold BLOB values}}

+do_execsql_test json1-3.1 {
+  SELECT json_replace('{"a":1,"b":2}','$.a','[3,4,5]');
+} {{{"a":"[3,4,5]","b":2}}}
+do_execsql_test json1-3.2 {
+  SELECT json_replace('{"a":1,"b":2}','$$.a','[3,4,5]');
+} {{{"a":[3,4,5],"b":2}}}
+do_execsql_test json1-3.3 {
+  SELECT json_type(json_set('{"a":1,"b":2}','$.b','{"x":3,"y":4}'),'$.b');
+} {text}
+do_execsql_test json1-3.4 {
+  SELECT json_type(json_set('{"a":1,"b":2}','$$.b','{"x":3,"y":4}'),'$.b');
+} {object}
+
+# Per rfc7159, any JSON value is allowed at the top level, and whitespace
+# is permitting before and/or after that value.
+#
+do_execsql_test json1-4.1 {
+  CREATE TABLE j1(x);
+  INSERT INTO j1(x)
+   VALUES('true'),('false'),('null'),('123'),('-234'),('34.5e+6'),
+         ('""'),('"\""'),('"\\"'),('"abcdefghijlmnopqrstuvwxyz"'),
+         ('[]'),('{}'),('[true,false,null,123,-234,34.5e+6,{},[]]'),
+         ('{"a":true,"b":{"c":false}}');
+  SELECT * FROM j1 WHERE NOT json_valid(x);
+} {}
+do_execsql_test json1-4.2 {
+  SELECT * FROM j1 WHERE NOT json_valid(char(0x20,0x09,0x0a,0x0d)||x);
+} {}
+do_execsql_test json1-4.3 {
+  SELECT * FROM j1 WHERE NOT json_valid(x||char(0x20,0x09,0x0a,0x0d));
+} {}
+
+# But an empty string, or a string of pure whitespace is not valid JSON.
+#
+do_execsql_test json1-4.4 {
+  SELECT json_valid(''), json_valid(char(0x20,0x09,0x0a,0x0d));
+} {0 0}
+
+# json_remove() and similar functions with no edit operations return their
+# input unchanged.
+#
+do_execsql_test json1-4.5 {
+  SELECT x FROM j1 WHERE json_remove(x)<>x;
+} {}
+do_execsql_test json1-4.6 {
+  SELECT x FROM j1 WHERE json_replace(x)<>x;
+} {}
+do_execsql_test json1-4.7 {
+  SELECT x FROM j1 WHERE json_set(x)<>x;
+} {}
+do_execsql_test json1-4.8 {
+  SELECT x FROM j1 WHERE json_insert(x)<>x;
+} {}
+
+# json_extract(JSON,'$') will return objects and arrays without change.
+#
+do_execsql_test json-4.10 {
+  SELECT count(*) FROM j1 WHERE json_type(x) IN ('object','array');
+  SELECT x FROM j1
+   WHERE json_extract(x,'$')<>x
+     AND json_type(x) IN ('object','array');
+} {4}
+
+do_execsql_test json-5.1 {
+  CREATE TABLE j2(id INTEGER PRIMARY KEY, json, src);
+  INSERT INTO j2(id,json,src)
+  VALUES(1,'{
+    "firstName": "John",
+    "lastName": "Smith",
+    "isAlive": true,
+    "age": 25,
+    "address": {
+      "streetAddress": "21 2nd Street",
+      "city": "New York",
+      "state": "NY",
+      "postalCode": "10021-3100"
+    },
+    "phoneNumbers": [
+      {
+        "type": "home",
+        "number": "212 555-1234"
+      },
+      {
+        "type": "office",
+        "number": "646 555-4567"
+      }
+    ],
+    "children": [],
+    "spouse": null
+  }','https://en.wikipedia.org/wiki/JSON');
+  INSERT INTO j2(id,json,src)
+  VALUES(2, '{
+	"id": "0001",
+	"type": "donut",
+	"name": "Cake",
+	"ppu": 0.55,
+	"batters":
+		{
+			"batter":
+				[
+					{ "id": "1001", "type": "Regular" },
+					{ "id": "1002", "type": "Chocolate" },
+					{ "id": "1003", "type": "Blueberry" },
+					{ "id": "1004", "type": "Devil''s Food" }
+				]
+		},
+	"topping":
+		[
+			{ "id": "5001", "type": "None" },
+			{ "id": "5002", "type": "Glazed" },
+			{ "id": "5005", "type": "Sugar" },
+			{ "id": "5007", "type": "Powdered Sugar" },
+			{ "id": "5006", "type": "Chocolate with Sprinkles" },
+			{ "id": "5003", "type": "Chocolate" },
+			{ "id": "5004", "type": "Maple" }
+		]
+   }','https://adobe.github.io/Spry/samples/data_region/JSONDataSetSample.html');
+   INSERT INTO j2(id,json,src)
+   VALUES(3,'[
+	{
+		"id": "0001",
+		"type": "donut",
+		"name": "Cake",
+		"ppu": 0.55,
+		"batters":
+			{
+				"batter":
+					[
+						{ "id": "1001", "type": "Regular" },
+						{ "id": "1002", "type": "Chocolate" },
+						{ "id": "1003", "type": "Blueberry" },
+						{ "id": "1004", "type": "Devil''s Food" }
+					]
+			},
+		"topping":
+			[
+				{ "id": "5001", "type": "None" },
+				{ "id": "5002", "type": "Glazed" },
+				{ "id": "5005", "type": "Sugar" },
+				{ "id": "5007", "type": "Powdered Sugar" },
+				{ "id": "5006", "type": "Chocolate with Sprinkles" },
+				{ "id": "5003", "type": "Chocolate" },
+				{ "id": "5004", "type": "Maple" }
+			]
+	},
+	{
+		"id": "0002",
+		"type": "donut",
+		"name": "Raised",
+		"ppu": 0.55,
+		"batters":
+			{
+				"batter":
+					[
+						{ "id": "1001", "type": "Regular" }
+					]
+			},
+		"topping":
+			[
+				{ "id": "5001", "type": "None" },
+				{ "id": "5002", "type": "Glazed" },
+				{ "id": "5005", "type": "Sugar" },
+				{ "id": "5003", "type": "Chocolate" },
+				{ "id": "5004", "type": "Maple" }
+			]
+	},
+	{
+		"id": "0003",
+		"type": "donut",
+		"name": "Old Fashioned",
+		"ppu": 0.55,
+		"batters":
+			{
+				"batter":
+					[
+						{ "id": "1001", "type": "Regular" },
+						{ "id": "1002", "type": "Chocolate" }
+					]
+			},
+		"topping":
+			[
+				{ "id": "5001", "type": "None" },
+				{ "id": "5002", "type": "Glazed" },
+				{ "id": "5003", "type": "Chocolate" },
+				{ "id": "5004", "type": "Maple" }
+			]
+	}
+   ]','https://adobe.github.io/Spry/samples/data_region/JSONDataSetSample.html');
+   SELECT count(*) FROM j2;
+} {3}
+
+do_execsql_test json-5.2 {
+  SELECT id, json_valid(json), json_type(json), '|' FROM j2 ORDER BY id;
+} {1 1 object | 2 1 object | 3 1 array |}
+
+ifcapable !vtab {
+  finish_test
+  return
+}
+
+# fullkey is always the same as path+key (with appropriate formatting)
+#
+do_execsql_test json-5.3 {
+  SELECT j2.rowid, jx.rowid, fullkey, path, key
+    FROM j2, json_tree(j2.json) AS jx
+   WHERE fullkey!=(path || CASE WHEN typeof(key)=='integer' THEN '['||key||']'
+                                ELSE '.'||key END);
+} {}
+do_execsql_test json-5.4 {
+  SELECT j2.rowid, jx.rowid, fullkey, path, key
+    FROM j2, json_each(j2.json) AS jx
+   WHERE fullkey!=(path || CASE WHEN typeof(key)=='integer' THEN '['||key||']'
+                                ELSE '.'||key END);
+} {}
+
+
+# Verify that the json_each.json and json_tree.json output is always the
+# same as input.
+#
+do_execsql_test json-5.5 {
+  SELECT j2.rowid, jx.rowid, fullkey, path, key
+    FROM j2, json_each(j2.json) AS jx
+   WHERE jx.json<>j2.json;
+} {}
+do_execsql_test json-5.6 {
+  SELECT j2.rowid, jx.rowid, fullkey, path, key
+    FROM j2, json_tree(j2.json) AS jx
+   WHERE jx.json<>j2.json;
+} {}
+do_execsql_test json-5.7 {
+  SELECT j2.rowid, jx.rowid, fullkey, path, key
+    FROM j2, json_each(j2.json) AS jx
+   WHERE jx.value<>jx.atom AND type NOT IN ('array','object');
+} {}
+do_execsql_test json-5.8 {
+  SELECT j2.rowid, jx.rowid, fullkey, path, key
+    FROM j2, json_tree(j2.json) AS jx
+   WHERE jx.value<>jx.atom AND type NOT IN ('array','object');
+} {}
+
+

 finish_test
--- a/test/rowid.test
+++ b/test/rowid.test
@@ -144,7 +144,8 @@ do_test rowid-2.8 {
  execsql {SELECT x FROM t1 ORDER BY x}
 } {1 3 5 7 9}

-if 0 {  # we can now....
+if 0 {  # With the index-on-expressions enhancement, creating
+        # an index on ROWID has become possible.
 # We cannot index by ROWID
 #
 do_test rowid-2.9 {
--- a/test/wal6.test
+++ b/test/wal6.test
@@ -193,5 +193,47 @@ do_test 3.x {
  db2 close
 } {}

+#-------------------------------------------------------------------------
+# Check that if a wal file has been partially checkpointed, no frames are
+# read from the checkpointed part.
+#
+reset_db
+do_execsql_test 4.1 {
+  PRAGMA page_size = 1024;
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(a, b);
+  CREATE TABLE t2(a, b);
+  PRAGMA wal_checkpoint = truncate;
+} {wal 0 0 0}
+
+do_test 4.2 {
+  execsql { INSERT INTO t1 VALUES(1, 2) }
+  file size test.db-wal
+} [wal_file_size 1 1024]
+
+do_test 4.3 {
+  sqlite3 db2 test.db
+  execsql { 
+    BEGIN;
+    INSERT INTO t2 VALUES(3, 4);
+  }
+  execsql { PRAGMA wal_checkpoint = passive } db2
+} {0 1 1}
+
+do_test 4.3 {
+  execsql { COMMIT }
+  db2 close
+  hexio_write test.db-wal 0 [string repeat 00 2000]
+  sqlite3 db2 test.db
+} {}
+
+do_test 4.4.1 { 
+  catchsql { SELECT * FROM t1 } db2 
+} {0 {1 2}}
+do_test 4.4.2 { 
+  catchsql { SELECT * FROM t2 } db2 
+} {1 {database disk image is malformed}}
+
+
 finish_test