diff --git a/ext/session/session4.test b/ext/session/session4.test
index 120a230b57..d07c57ffd6 100644
--- a/ext/session/session4.test
+++ b/ext/session/session4.test
@@ -64,4 +64,29 @@ do_test 1.3 {
   list [catch { sqlite3changeset_apply db $x xConflict } msg] $msg
 } {1 SQLITE_CORRUPT}
 
+#-------------------------------------------------------------------------
+reset_db
+do_execsql_test 2.0 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY,b,c,d);
+  CREATE TABLE t2(e TEXT PRIMARY KEY NOT NULL,f,g);
+  CREATE TABLE t3(w REAL PRIMARY KEY NOT NULL,x,y);
+  CREATE TABLE t4(z PRIMARY KEY) WITHOUT ROWID;
+}
+
+foreach {tn blob} {
+  1 {54010174340012000000}
+  2 {54fefe8bcb0012000300}
+  3 {5480809280808001017434001200fb}
+  4 {50af9c939c9c9cb09c9c6400b09c9c6400}
+  5 {12000300}
+  6 {09847304}
+  7 {5401017434001208}
+} {
+if {$tn==7} breakpoint
+  do_test 2.$tn {
+    set changeset [binary decode hex $blob]
+    list [catch { sqlite3changeset_apply db $changeset xConflict } msg] $msg
+  } {1 SQLITE_CORRUPT}
+}
+
 finish_test
diff --git a/ext/session/sqlite3session.c b/ext/session/sqlite3session.c
index bdecdd1031..2a130c7e9e 100644
--- a/ext/session/sqlite3session.c
+++ b/ext/session/sqlite3session.c
@@ -2718,15 +2718,18 @@ static int sessionReadRecord(
   for(i=0; i<nCol && rc==SQLITE_OK; i++){
     int eType = 0;                /* Type of value (SQLITE_NULL, TEXT etc.) */
     if( abPK && abPK[i]==0 ) continue;
-    rc = sessionInputBuffer(pIn, 9);
+    if( pIn->iNext>=pIn->nData ){
+      rc = SQLITE_CORRUPT;
+    }else{
+      rc = sessionInputBuffer(pIn, 9);
+    }
     if( rc==SQLITE_OK ){
       eType = pIn->aData[pIn->iNext++];
-    }
-
-    assert( apOut[i]==0 );
-    if( eType ){
-      apOut[i] = sqlite3ValueNew(0);
-      if( !apOut[i] ) rc = SQLITE_NOMEM;
+      assert( apOut[i]==0 );
+      if( eType ){
+        apOut[i] = sqlite3ValueNew(0);
+        if( !apOut[i] ) rc = SQLITE_NOMEM;
+      }
     }
 
     if( rc==SQLITE_OK ){
@@ -2857,11 +2860,15 @@ static int sessionChangesetReadTblhdr(sqlite3_changeset_iter *p){
     int nByte;
     int nVarint;
     nVarint = sessionVarintGet(&p->in.aData[p->in.iNext], &p->nCol);
-    nCopy -= nVarint;
-    p->in.iNext += nVarint;
-    nByte = p->nCol * sizeof(sqlite3_value*) * 2 + nCopy;
-    p->tblhdr.nBuf = 0;
-    sessionBufferGrow(&p->tblhdr, nByte, &rc);
+    if( p->nCol>0 ){
+      nCopy -= nVarint;
+      p->in.iNext += nVarint;
+      nByte = p->nCol * sizeof(sqlite3_value*) * 2 + nCopy;
+      p->tblhdr.nBuf = 0;
+      sessionBufferGrow(&p->tblhdr, nByte, &rc);
+    }else{
+      rc = SQLITE_CORRUPT;
+    }
   }
 
   if( rc==SQLITE_OK ){
@@ -2939,6 +2946,13 @@ static int sessionChangesetNext(
     op = p->in.aData[p->in.iNext++];
   }
 
+  if( p->zTab==0 ){
+    /* The first record in the changeset is not a table header. Must be a
+    ** corrupt changeset. */
+    assert( p->in.iNext==1 );
+    return (p->rc = SQLITE_CORRUPT_BKPT);
+  }
+
   p->op = op;
   p->bIndirect = p->in.aData[p->in.iNext++];
   if( p->op!=SQLITE_UPDATE && p->op!=SQLITE_DELETE && p->op!=SQLITE_INSERT ){
@@ -3708,7 +3722,13 @@ static int sessionBindRow(
     if( !abPK || abPK[i] ){
       sqlite3_value *pVal;
       (void)xValue(pIter, i, &pVal);
-      rc = sessionBindValue(pStmt, i+1, pVal);
+      if( pVal==0 ){
+        /* The value in the changeset was "undefined". This indicates a
+        ** corrupt changeset blob.  */
+        rc = SQLITE_CORRUPT;
+      }else{
+        rc = sessionBindValue(pStmt, i+1, pVal);
+      }
     }
   }
   return rc;
diff --git a/manifest b/manifest
index 07d15b424e..f09706c7be 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Enhance\sthe\ssessions\sdocumentation\sto\sshow\sthe\smethods\sof\sthe\svarious\sobjects.
-D 2018-02-28T22:21:29.549
+C Fix\ssome\scrashes\sin\sthe\ssqlite3changeset_apply()\sfunction\sthat\scould\sbe\scaused\nby\scorrupt\schangeset\sblobs.
+D 2018-03-01T12:05:51.293
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in a2d2fb8d17c39ab5ec52beb27850b903949080848236923f436156b72a958737
@@ -381,7 +381,7 @@ F ext/session/changeset.c 4ccbaa4531944c24584bf6a61ba3a39c62b6267a
 F ext/session/session1.test 736d7ff178662f0b717c37f46531b84a5ce0210ccb0c4edf629c55dbcbbc3ea1
 F ext/session/session2.test 284de45abae4cc1082bc52012ee81521d5ac58e0
 F ext/session/session3.test ce9ce3dfa489473987f899e9f6a0f2db9bde3479
-F ext/session/session4.test 457b02bdc349eb01151e54de014df77abd3c08c8
+F ext/session/session4.test 488539cee1d2510b415236fac2727575f4110e7609a500eb21c8d9e517dfff38
 F ext/session/session5.test 716bc6fafd625ce60dfa62ae128971628c1a1169
 F ext/session/session6.test 443789bc2fca12e4f7075cf692c60b8a2bea1a26
 F ext/session/session8.test 8e194b3f655d861ca36de5d4de53f702751bab3b
@@ -402,7 +402,7 @@ F ext/session/sessionfault.test da273f2712b6411e85e71465a1733b8501dbf6f7
 F ext/session/sessionfault2.test 04aa0bc9aa70ea43d8de82c4f648db4de1e990b0
 F ext/session/sessionstat1.test 41cd97c2e48619a41cdf8ae749e1b25f34719de638689221aa43971be693bf4e
 F ext/session/sessionwor.test 2f3744236dc8b170a695b7d8ddc8c743c7e79fdc
-F ext/session/sqlite3session.c a5b7aed647abe7e366254b755597fce3f2719d82c98990cb0e1e07a3d203fe2b
+F ext/session/sqlite3session.c bd8e52f8b4adef1d886564655030d5a7675baf59d52542c8f7eda99971048e13
 F ext/session/sqlite3session.h b4de978c24a48a0d9b3b92ddfb749f4b07461766325ee950f5ecb8384c10606f
 F ext/session/test_session.c eb0bd6c1ea791c1d66ee4ef94c16500dad936386
 F ext/userauth/sqlite3userauth.h 7f3ea8c4686db8e40b0a0e7a8e0b00fac13aa7a3
@@ -1708,7 +1708,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P c949b915e893e917315ce21092d4c4bbd3e1b88d5326928f71dcc2f18f300702
-R 6f69334171b7b3454d79aa33bdfe9b61
-U drh
-Z 67038639e12c985c1bd40cee53ce76b7
+P e01177754ad6d9e2d38adddddd2e2e212094dac1154bda5fcee61ca8b678ae0f
+R 72900d8c116195630f7d9bfcd1153ca1
+U dan
+Z e1e8f32ef49baada43e1fbc29b2fefd6
diff --git a/manifest.uuid b/manifest.uuid
index 36563f126d..bad79d7fbb 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e01177754ad6d9e2d38adddddd2e2e212094dac1154bda5fcee61ca8b678ae0f
\ No newline at end of file
+745a9a7fef0f28a57ea3f44899058993f6ecdedda52c81a09a4a9ce09c9004d6
\ No newline at end of file