Refactor the sqlite3_normalized_sql() implementation. This is a

work-in-progress. There are still issues.

FossilOrigin-Name: a4c890b0af9786295e6df05022009d8946550adb873535c610be805c2b7a4083

manifest

@@ -1,5 +1,5 @@
-C Add\ssupport\sfor\sthe\sVACUUM\sINTO\scommand.
+C Refactor\sthe\ssqlite3_normalized_sql()\simplementation.\sThis\sis\sa\nwork-in-progress.\sThere\sare\sstill\sissues.
-D 2018-12-10T01:48:29.276
+D 2018-12-10T16:00:57.538
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 68d0ba0f0b533d5bc84c78c13a6ce84ee81183a67014caa47a969e67f028fa1c
@@ -502,7 +502,7 @@ F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
 F src/pcache1.c ad0ffc5b35b0280d045ac569d34d4b842e3e6a4a118f6396b320987a0957afcc
 F src/pragma.c 96ce7dce4dc9cb2b7aa0e1b2ce7536870bdc00b10becc278245e775489447ea0
 F src/pragma.h fdd03d78a7497f74a3f652909f945328480089189526841ae829ce7313d98d13
-F src/prepare.c be449edb106a16f1ad95f9b798bdc2337f8c3f83b96c284f417c0a26d43f0c1b
+F src/prepare.c 0e8fc0deaf36da104e08d07ce7d97bc09ab57d078b399381532fec3fa1d3f2bb
 F src/printf.c 0f1177cf1dd4d7827bf64d840768514ec76409abecaca9e8b577dbd065150381
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 095d1d41d7a981ee9db8bfeae25ed0d6a8a5e5e3d66b0f4efd71877ed7b56132
@@ -512,7 +512,7 @@ F src/shell.c.in 5f38bd0e127c2cc4e506b5c3565c10879ddfae6c2d867bb5972563e40717c19
 F src/sqlite.h.in 908ec406feefc4c7e1486a2e3dc30a8bfb51c5a345a8e8130ac201962db171c4
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 960f1b86c3610fa23cb6a267572a97dcf286e77aa0dd3b9b23292ffaa1ea8683
-F src/sqliteInt.h 70ce5e14c887554d3c51f2045f5a95b6e83de745d7f6448e79e49fdd8dfc2d5c
+F src/sqliteInt.h 369d4774d97643e26085e0ea4cdee6afeadaa27670193b9eebaea8c95687fad0
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -570,7 +570,7 @@ F src/test_windirent.h 90dfbe95442c9762357fe128dc7ae3dc199d006de93eb33ba3972e0a9
 F src/test_window.c cdae419fdcea5bad6dcd9368c685abdad6deb59e9fc8b84b153de513d394ba3f
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
-F src/tokenize.c 9e781e1ca80eefe7b5d6a9e2cd5c678c847da55fd6f093781fad7950934d4c83
+F src/tokenize.c a43ecbafefceb475522f17d6f92d64193a755fe3f35615dfca13340c81ca3872
 F src/treeview.c 7b12ac059de54c939b6eb0dbffc9410c29c80d2470cee5cbe07d5ff9ea2d9253
 F src/trigger.c d3d78568f37fb2e6cdcc2d1e7b60156f15b0b600adec55b83c5d42f6cad250bd
 F src/update.c 1816d56c1bca1ba4e0ef98cac2f49be62858e9df1dc08844c7067eb41cc44274
@@ -579,10 +579,10 @@ F src/utf.c 810fbfebe12359f10bc2a011520a6e10879ab2a163bcb26c74768eab82ea62a5
 F src/util.c d9eb0a6c4aae1b00a7369eadd7ca0bbe946cb4c953b6751aa20d357c2f482157
 F src/vacuum.c 3ffe64ecfc94b7528c5d7bdb1c3a19d72fec63f2aa846e3b90f8de5dbbddf5aa
 F src/vdbe.c 55bafc424748d9ed505ab2680736e51d1bb05c01e9885cbb3b287b51dc8b47ec
-F src/vdbe.h d82f323d581b36b8e147d650257ef34e0e93790039b6cbda45c321c275f7595e
+F src/vdbe.h 8990d668a89890a33326b0a29b992c4014b72f3b6cdcd9ee0e190593c247f9b0
 F src/vdbeInt.h 73f5051923f3f29779bfc374c0c68e23b8e5e3792def2e33e51b427edb890abd
 F src/vdbeapi.c 9709452bee82963e1f7f1f5d0c71db823d553f8dbb2c47a911c4983d537a1947
-F src/vdbeaux.c 9a9617666124e18cbd6e936740f7469dcf0d82867b1abf9ed828694500930b64
+F src/vdbeaux.c c72fc6015e52c212d6c6db7cee04bfbfbd681106f551c9296812a73082fb09d6
 F src/vdbeblob.c f5c70f973ea3a9e915d1693278a5f890dc78594300cf4d54e64f2b0917c94191
 F src/vdbemem.c 7b3305bc4a5139f4536ac9b5f61da0f915e49d2e3fdfa87dfdfa9d7aba8bc1e9
 F src/vdbesort.c 90aad5a92608f2dd771c96749beabdb562c9d881131a860a7a5bccf66dc3be7f
@@ -1783,8 +1783,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P b7bf3c9832bde26b359f4d58ebcf7788c500586d311387d022192ed65a126252 9748d7995bc1dd632d66d2d326048d50e29c6f5e6993d5a6294d14421d2cb72f
+P 77f150b8b46761f4f62f9d8926c10a95a70589a4525393fc16b321bd98c083a7
-R f78f1915a996819be59599569cf251be
+R d755f31eec9cdb1a3415665c2aacb5ab
-T +closed 9748d7995bc1dd632d66d2d326048d50e29c6f5e6993d5a6294d14421d2cb72f
+T *branch * normalize-refactor
+T *sym-normalize-refactor *
+T -sym-trunk *
 U drh
-Z ee3d9a1eeb178b5acf328ec54a590f24
+Z f90c6b85a4f2311f0e8b3d6a605ae025

manifest.uuid

@@ -1 +1 @@
-77f150b8b46761f4f62f9d8926c10a95a70589a4525393fc16b321bd98c083a7
+a4c890b0af9786295e6df05022009d8946550adb873535c610be805c2b7a4083

src/prepare.c

@@ -709,204 +709,6 @@ static int sqlite3LockAndPrepare(
   return rc;
 }
 
-#ifdef SQLITE_ENABLE_NORMALIZE
-
-/*
-** Attempt to estimate the final output buffer size needed for the fully
-** normalized version of the specified SQL string.  This should take into
-** account any potential expansion that could occur (e.g. via IN clauses
-** being expanded, etc).  This size returned is the total number of bytes
-** including the NUL terminator.
-*/
-static int estimateNormalizedSize(
-  const char *zSql, /* The original SQL string */
-  int nSql          /* Length of original SQL string */
-){
-  int nOut = nSql + 4;
-  const char *z = zSql;
-  while( nOut<nSql*5 ){
-    while( z[0]!=0 && z[0]!='I' && z[0]!='i' ){ z++; }
-    if( z[0]==0 ) break;
-    z++;
-    if( z[0]!='N' && z[0]!='n' ) break;
-    z++;
-    while( sqlite3Isspace(z[0]) ){ z++; }
-    if( z[0]!='(' ) break;
-    z++;
-    nOut += 5; /* ?,?,? */
-  }
-  return nOut;
-}
-
-/*
-** Copy the current token into the output buffer while dealing with quoted
-** identifiers.  By default, all letters will be converted into lowercase.
-** If the bUpper flag is set, uppercase will be used.  The piOut argument
-** will be used to update the target index into the output string.
-*/
-static void copyNormalizedToken(
-  const char *zSql, /* The original SQL string */
-  int iIn,          /* Current index into the original SQL string */
-  int nToken,       /* Number of bytes in the current token */
-  int tokenFlags,   /* Flags returned by the tokenizer */
-  char *zOut,       /* The output string */
-  int *piOut        /* Pointer to target index into the output string */
-){
-  int bQuoted = tokenFlags & SQLITE_TOKEN_QUOTED;
-  int bKeyword = tokenFlags & SQLITE_TOKEN_KEYWORD;
-  int j = *piOut, k = 0;
-  for(; k<nToken; k++){
-    if( bQuoted ){
-      if( k==0 && iIn>0 ){
-        zOut[j++] = '"';
-        continue;
-      }else if( k==nToken-1 ){
-        zOut[j++] = '"';
-        continue;
-      }
-    }
-    if( bKeyword ){
-      zOut[j++] = sqlite3Toupper(zSql[iIn+k]);
-    }else{
-      zOut[j++] = sqlite3Tolower(zSql[iIn+k]);
-    }
-  }
-  *piOut = j;
-}
-
-/*
-** Compute a normalization of the SQL given by zSql[0..nSql-1].  Return
-** the normalization in space obtained from sqlite3DbMalloc().  Or return
-** NULL if anything goes wrong or if zSql is NULL.
-*/
-char *sqlite3Normalize(
-  Vdbe *pVdbe,      /* VM being reprepared */
-  const char *zSql, /* The original SQL string */
-  int nSql          /* Size of the input string in bytes */
-){
-  sqlite3 *db;           /* Database handle. */
-  char *z;               /* The output string */
-  int nZ;                /* Size of the output string in bytes */
-  int i;                 /* Next character to read from zSql[] */
-  int j;                 /* Next character to fill in on z[] */
-  int tokenType = 0;     /* Type of the next token */
-  int prevTokenType = 0; /* Type of the previous token, except spaces */
-  int n;                 /* Size of the next token */
-  int nParen = 0;        /* Nesting level of parenthesis */
-  int iStartIN = 0;      /* Start of RHS of IN operator in z[] */
-  int nParenAtIN = 0;    /* Value of nParent at start of RHS of IN operator */
-
-  db = sqlite3VdbeDb(pVdbe);
-  assert( db!=0 );
-  if( zSql==0 ) return 0;
-  nZ = estimateNormalizedSize(zSql, nSql);
-  z = sqlite3DbMallocRawNN(db, nZ);
-  if( z==0 ) goto normalizeError;
-  for(i=j=0; i<nSql && zSql[i]; i+=n){
-    int flags = 0;
-    if( tokenType!=TK_SPACE ) prevTokenType = tokenType;
-    n = sqlite3GetTokenNormalized((unsigned char*)zSql+i, &tokenType, &flags);
-    switch( tokenType ){
-      case TK_SPACE: {
-        break;
-      }
-      case TK_ILLEGAL: {
-        goto normalizeError;
-      }
-      case TK_STRING:
-      case TK_INTEGER:
-      case TK_FLOAT:
-      case TK_VARIABLE:
-      case TK_BLOB: {
-        z[j++] = '?';
-        break;
-      }
-      case TK_LP:
-      case TK_RP: {
-        if( tokenType==TK_LP ){
-          nParen++;
-          if( prevTokenType==TK_IN ){
-            iStartIN = j;
-            nParenAtIN = nParen;
-          }
-        }else{
-          if( iStartIN>0 && nParen==nParenAtIN ){
-            assert( iStartIN+6<nZ );
-            memcpy(z+iStartIN+1, "?,?,?", 5);
-            j = iStartIN+6;
-            assert( nZ-1-j>=0 );
-            assert( nZ-1-j<nZ );
-            memset(z+j, 0, nZ-1-j);
-            iStartIN = 0;
-          }
-          nParen--;
-        }
-        assert( nParen>=0 );
-        /* Fall through */
-      }
-      case TK_MINUS:
-      case TK_SEMI:
-      case TK_PLUS:
-      case TK_STAR:
-      case TK_SLASH:
-      case TK_REM:
-      case TK_EQ:
-      case TK_LE:
-      case TK_NE:
-      case TK_LSHIFT:
-      case TK_LT:
-      case TK_RSHIFT:
-      case TK_GT:
-      case TK_GE:
-      case TK_BITOR:
-      case TK_CONCAT:
-      case TK_COMMA:
-      case TK_BITAND:
-      case TK_BITNOT:
-      case TK_DOT:
-      case TK_IN:
-      case TK_IS:
-      case TK_NOT:
-      case TK_NULL:
-      case TK_ID: {
-        if( tokenType==TK_NULL ){
-          if( prevTokenType==TK_IS || prevTokenType==TK_NOT ){
-            /* NULL is a keyword in this case, not a literal value */
-          }else{
-            /* Here the NULL is a literal value */
-            z[j++] = '?';
-            break;
-          }
-        }
-        if( j>0 && sqlite3IsIdChar(z[j-1]) && sqlite3IsIdChar(zSql[i]) ){
-          z[j++] = ' ';
-        }
-        if( tokenType==TK_ID ){
-          if( zSql[i]=='"'
-           && sqlite3VdbeUsesDoubleQuotedString(db,pVdbe,zSql+i,n)
-          ){
-            z[j++] = '?';
-            break;
-          }
-          if( nParen==nParenAtIN ) iStartIN = 0;
-        }
-        copyNormalizedToken(zSql, i, n, flags, z, &j);
-        break;
-      }
-    }
-  }
-  assert( j<nZ && "one" );
-  while( j>0 && z[j-1]==' ' ){ j--; }
-  if( j>0 && z[j-1]!=';' ){ z[j++] = ';'; }
-  z[j] = 0;
-  assert( j<nZ && "two" );
-  return z;
-
-normalizeError:
-  sqlite3DbFree(db, z);
-  return 0;
-}
-#endif /* SQLITE_ENABLE_NORMALIZE */
 
 /*
 ** Rerun the compilation of a statement after a schema change.

src/sqliteInt.h

@@ -4255,9 +4255,6 @@ void sqlite3AlterFunctions(void);
 void sqlite3AlterRenameTable(Parse*, SrcList*, Token*);
 void sqlite3AlterRenameColumn(Parse*, SrcList*, Token*, Token*);
 int sqlite3GetToken(const unsigned char *, int *);
-#ifdef SQLITE_ENABLE_NORMALIZE
-int sqlite3GetTokenNormalized(const unsigned char *, int *, int *);
-#endif
 void sqlite3NestedParse(Parse*, const char*, ...);
 void sqlite3ExpirePreparedStatements(sqlite3*, int);
 int sqlite3CodeSubselect(Parse*, Expr *, int, int);

src/tokenize.c

@@ -545,73 +545,6 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
   return i;
 }
 
-#ifdef SQLITE_ENABLE_NORMALIZE
-/*
-** Return the length (in bytes) of the token that begins at z[0].
-** Store the token type in *tokenType before returning.  If flags has
-** SQLITE_TOKEN_NORMALIZE flag enabled, use the identifier token type
-** for keywords.  Add SQLITE_TOKEN_QUOTED to flags if the token was
-** actually a quoted identifier.  Add SQLITE_TOKEN_KEYWORD to flags
-** if the token was recognized as a keyword; this is useful when the
-** SQLITE_TOKEN_NORMALIZE flag is used, because it enables the caller
-** to differentiate between a keyword being treated as an identifier
-** (for normalization purposes) and an actual identifier.
-*/
-int sqlite3GetTokenNormalized(
-  const unsigned char *z,
-  int *tokenType,
-  int *flags
-){
-  int n;
-  unsigned char iClass = aiClass[*z];
-  if( iClass==CC_KYWD ){
-    int i;
-    for(i=1; aiClass[z[i]]<=CC_KYWD; i++){}
-    if( IdChar(z[i]) ){
-      /* This token started out using characters that can appear in keywords,
-      ** but z[i] is a character not allowed within keywords, so this must
-      ** be an identifier instead */
-      i++;
-      while( IdChar(z[i]) ){ i++; }
-      *tokenType = TK_ID;
-      return i;
-    }
-    *tokenType = TK_ID;
-    n = keywordCode((char*)z, i, tokenType);
-    /* If the token is no longer considered to be an identifier, then it is a
-    ** keyword of some kind.  Make the token back into an identifier and then
-    ** set the SQLITE_TOKEN_KEYWORD flag.  Several non-identifier tokens are
-    ** used verbatim, including IN, IS, NOT, and NULL. */
-    switch( *tokenType ){
-      case TK_ID: {
-        /* do nothing, handled by caller */
-        break;
-      }
-      case TK_IN:
-      case TK_IS:
-      case TK_NOT:
-      case TK_NULL: {
-        *flags |= SQLITE_TOKEN_KEYWORD;
-        break;
-      }
-      default: {
-        *tokenType = TK_ID;
-        *flags |= SQLITE_TOKEN_KEYWORD;
-        break;
-      }
-    }
-  }else{
-    n = sqlite3GetToken(z, tokenType);
-    /* If the token is considered to be an identifier and the character class
-    ** of the first character is a quote, set the SQLITE_TOKEN_QUOTED flag. */
-    if( *tokenType==TK_ID && (iClass==CC_QUOTE || iClass==CC_QUOTE2) ){
-      *flags |= SQLITE_TOKEN_QUOTED;
-    }
-  }
-  return n;
-}
-#endif /* SQLITE_ENABLE_NORMALIZE */
-
 /*
 ** Run the parser on the given SQL string.  The parser structure is
 ** passed in.  An SQLITE_ status code is returned.  If an error occurs
@@ -781,3 +714,133 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
   assert( nErr==0 || pParse->rc!=SQLITE_OK );
   return nErr;
 }
+
+
+#ifdef SQLITE_ENABLE_NORMALIZE
+/*
+** Insert a single space character into pStr if the current string
+** ends with an identifier
+*/
+static void addSpaceSeparator(sqlite3_str *pStr){
+  if( pStr->nChar && sqlite3IsIdChar(pStr->zText[pStr->nChar-1]) ){
+    sqlite3_str_append(pStr, " ", 1);
+  }
+}
+
+/*
+** Compute a normalization of the SQL given by zSql[0..nSql-1].  Return
+** the normalization in space obtained from sqlite3DbMalloc().  Or return
+** NULL if anything goes wrong or if zSql is NULL.
+*/
+char *sqlite3Normalize(
+  Vdbe *pVdbe,       /* VM being reprepared */
+  const char *zSql,  /* The original SQL string */
+  int nSql           /* Size of the input string in bytes */
+){
+  sqlite3 *db;       /* The database connection */
+  int i;             /* Next unread byte of zSql[] */
+  int n;             /* length of current token */
+  int tokenType;     /* type of current token */
+  int prevType;      /* Previous non-whitespace token */
+  int nParen;        /* Number of nested levels of parentheses */
+  int iStartIN;      /* Start of RHS of IN operator in z[] */
+  int nParenAtIN;    /* Value of nParent at start of RHS of IN operator */
+  int j;             /* Bytes of normalized SQL generated so far */
+  sqlite3_str *pStr; /* The normalized SQL string under construction */
+
+  if( zSql==0 || nSql==0 ) return 0;
+  db = sqlite3VdbeDb(pVdbe);
+  tokenType = -1;
+  nParen = iStartIN = nParenAtIN = 0;
+  pStr = sqlite3_str_new(db);
+  for(i=0; i<nSql && pStr->accError==0; i+=n){
+    if( tokenType!=TK_SPACE ){
+      prevType = tokenType;
+    }
+    n = sqlite3GetToken((unsigned char*)zSql+i, &tokenType);
+    if( NEVER(n<=0) ) break;
+    switch( tokenType ){
+      case TK_SPACE: {
+        break;
+      }
+      case TK_NULL: {
+        if( prevType==TK_IS || prevType==TK_NOT ){
+          sqlite3_str_append(pStr, " NULL", 5);
+          break;
+        }
+        /* Fall through */
+      }
+      case TK_STRING:
+      case TK_INTEGER:
+      case TK_FLOAT:
+      case TK_VARIABLE:
+      case TK_BLOB: {
+        sqlite3_str_append(pStr, "?", 1);
+        break;
+      }
+      case TK_LP: {
+        nParen++;
+        if( prevType==TK_IN ){
+          iStartIN = pStr->nChar;
+          nParenAtIN = nParen;
+        }
+        sqlite3_str_append(pStr, "(", 1);
+        break;
+      }
+      case TK_RP: {
+        if( iStartIN>0 && nParen==nParenAtIN ){
+          assert( pStr->nChar>=iStartIN );
+          pStr->nChar = iStartIN+1;
+          sqlite3_str_append(pStr, "?,?,?", 5);
+          iStartIN = 0;
+        }
+        nParen--;
+        sqlite3_str_append(pStr, ")", 1);
+        break;
+      }
+      case TK_ID: {
+        j = pStr->nChar;
+        if( sqlite3Isquote(zSql[i]) ){
+          char *zId = sqlite3DbStrNDup(db, zSql+i, n);
+          int nId;
+          int eType = 0;
+          if( zId==0 ) break;
+          sqlite3Dequote(zId);
+          if( zSql[i]=='"' && sqlite3VdbeUsesDoubleQuotedString(pVdbe, zId) ){
+            sqlite3_str_append(pStr, "?", 1);
+            sqlite3DbFree(db, zId);
+            break;
+          }
+          nId = sqlite3Strlen30(zId);
+          if( sqlite3GetToken((u8*)zId, &eType)==nId && eType==TK_ID ){
+            addSpaceSeparator(pStr);
+            sqlite3_str_append(pStr, zId, nId);
+          }else{
+            sqlite3_str_appendf(pStr, "\"%w\"", zId);
+          }
+          sqlite3DbFree(db, zId);
+        }else{
+          addSpaceSeparator(pStr);
+          sqlite3_str_append(pStr, zSql+i, n);
+        }
+        while( j<pStr->nChar ){
+          pStr->zText[j] = sqlite3Tolower(pStr->zText[j]);
+          j++;
+        }
+        break;
+      }
+      default: {
+        if( sqlite3IsIdChar(zSql[i]) ) addSpaceSeparator(pStr);
+        j = pStr->nChar;
+        sqlite3_str_append(pStr, zSql+i, n);
+        while( j<pStr->nChar ){
+          pStr->zText[j] = sqlite3Toupper(pStr->zText[j]);
+          j++;
+        }
+        break;
+      }
+    }
+  }
+  return sqlite3_str_finish(pStr);
+}
+#endif /* SQLITE_ENABLE_NORMALIZE */

src/vdbe.h

@@ -253,7 +253,7 @@ u8 sqlite3VdbePrepareFlags(Vdbe*);
 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, u8);
 #ifdef SQLITE_ENABLE_NORMALIZE
 void sqlite3VdbeAddDblquoteStr(sqlite3*,Vdbe*,const char*);
-int sqlite3VdbeUsesDoubleQuotedString(sqlite3*,Vdbe*,const char*,int);
+int sqlite3VdbeUsesDoubleQuotedString(Vdbe*,const char*);
 #endif
 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);

src/vdbeaux.c

@@ -97,26 +97,16 @@ void sqlite3VdbeAddDblquoteStr(sqlite3 *db, Vdbe *p, const char *z){
 ** that identifier is really used as a string literal.
 */
 int sqlite3VdbeUsesDoubleQuotedString(
-  sqlite3 *db,            /* Used for transient malloc */
   Vdbe *pVdbe,            /* The prepared statement */
-  const char *zId,        /* The double-quoted identifier */
+  const char *zId         /* The double-quoted identifier, already dequoted */
-  int nId                 /* Bytes in zId, which is not zero-terminated */
 ){
-  char *z;
   DblquoteStr *pStr;
   assert( zId!=0 );
-  assert( zId[0]=='"' );
-  assert( nId>=2 );
-  assert( zId[nId-1]=='"' );
   if( pVdbe->pDblStr==0 ) return 0;
-  z = sqlite3DbStrNDup(db, zId, nId);
-  if( z==0 ) return 0;
-  sqlite3Dequote(z);
   for(pStr=pVdbe->pDblStr; pStr; pStr=pStr->pNextStr){
-    if( strcmp(z, pStr->z)==0 ) break;
+    if( strcmp(zId, pStr->z)==0 ) return 1;
   }
-  sqlite3DbFree(db, z);
+  return 0;
-  return pStr!=0;
 }
 #endif