Fix sqlite3VdbeExpandSql() so that it handles OOMs by always returning NULL.

FossilOrigin-Name: 5a027fe4127d498e0dc0d9439131c6a29085cf0a

manifest

@@ -1,5 +1,5 @@
-C Be\ssure\sto\shold\sthe\sdatabase\sconnection\smutex\swhile\scalling\ssqlite3VdbeExpand()\nfrom\swithin\ssqlite3_expanded_sql().
-D 2016-07-22T20:45:03.857
+C Fix\ssqlite3VdbeExpandSql()\sso\sthat\sit\shandles\sOOMs\sby\salways\sreturning\sNULL.
+D 2016-07-23T00:43:14.540
 F Makefile.in 6c20d44f72d4564f11652b26291a214c8367e5db
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc d66d0395c38571aab3804f8db0fa20707ae4609a
@@ -453,11 +453,11 @@ F src/vdbe.c 7b5570f77e32766949fd8f9478e4a9bb06e6ab24
 F src/vdbe.h 67bc551f7faf04c33493892e4b378aada823ed10
 F src/vdbeInt.h c59381049af5c7751a83456c39b80d1a6fde1f9d
 F src/vdbeapi.c 460b90f7f0894753d33df377702c1dc9cc5fa21b
-F src/vdbeaux.c 7a09b945ebc4893e3a15bd68c4634d4aff34ebd5
+F src/vdbeaux.c 8557563e9b0fed6ba05b0ce42e3b3049d93f26fa
 F src/vdbeblob.c 83d2d266383157b02e2b809350bb197e89d7895b
 F src/vdbemem.c 1ecaa5ee0caff07255f25d04e8dc88befb6f88d1
 F src/vdbesort.c 91fda3909326860382b0ca8aa251e609c6a9d62c
-F src/vdbetrace.c d0371769fe66fe4eb85bdcacf82b6f2af50feb9b
+F src/vdbetrace.c bea16fb07070b33f6efdece3169c3c4b423894a8
 F src/vtab.c 948d2d4984219eee37a7bf427d6667e21e6eb92e
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 02eeecc265f6ffd0597378f5d8ae9070b62a406a
@@ -1506,7 +1506,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 409535e6dfc307f26ea3d9f51be51c439b6d7b22
-R 2b4fbb49220ef1cdb35ff0cc787c0937
+P 527b5ba68c0b0185958b945b197f9022951d9379
+R e119b9614fe99fd5a44e65f51db3182b
 U drh
-Z 1a401e59c5d6714d520ae3898a7c3c7e
+Z 16700eecfd0a8ed6af44720c8587b7e0

manifest.uuid

@@ -1 +1 @@
-527b5ba68c0b0185958b945b197f9022951d9379
+5a027fe4127d498e0dc0d9439131c6a29085cf0a

src/vdbeaux.c

@@ -85,12 +85,14 @@ char *sqlite3_expanded_sql(sqlite3_stmt *pStmt){
 #ifdef SQLITE_OMIT_TRACE
   return 0;
 #else
-  Vdbe *p = (Vdbe *)pStmt;
-  char *z;
-  if( p==0 || p->zSql==0 ) return 0;
-  sqlite3_mutex_enter(p->db->mutex);
-  z = sqlite3VdbeExpandSql(p, p->zSql);
-  sqlite3_mutex_leave(p->db->mutex);
+  char *z = 0;
+  const char *zSql = sqlite3_sql(pStmt);
+  if( zSql ){
+    Vdbe *p = (Vdbe *)pStmt;
+    sqlite3_mutex_enter(p->db->mutex);
+    z = sqlite3VdbeExpandSql(p, zSql);
+    sqlite3_mutex_leave(p->db->mutex);
+  }
   return z;
 #endif
 }

src/vdbetrace.c

@@ -81,6 +81,9 @@ char *sqlite3VdbeExpandSql(
   int i;                   /* Loop counter */
   Mem *pVar;               /* Value of a host parameter */
   StrAccum out;            /* Accumulate the output here */
+#ifndef SQLITE_OMIT_UTF16
+  Mem utf8;                /* Used to convert UTF16 parameters into UTF8 for display */
+#endif
   char zBase[100];         /* Initial working space */
 
   db = p->db;
@@ -135,12 +138,16 @@ char *sqlite3VdbeExpandSql(
         int nOut;  /* Number of bytes of the string text to include in output */
 #ifndef SQLITE_OMIT_UTF16
         u8 enc = ENC(db);
-        Mem utf8;
         if( enc!=SQLITE_UTF8 ){
           memset(&utf8, 0, sizeof(utf8));
           utf8.db = db;
-          sqlite3VdbeMemSetStr(&utf8, pVar->z, pVar->n, enc, SQLITE_STATIC);
-          sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8);
+          if( SQLITE_NOMEM== sqlite3VdbeMemSetStr(&utf8,pVar->z,pVar->n,enc,SQLITE_STATIC)
+           || SQLITE_NOMEM== sqlite3VdbeChangeEncoding(&utf8, SQLITE_UTF8)
+          ){
+            sqlite3StrAccumReset(&out);
+            sqlite3VdbeMemRelease(&utf8);
+            return 0;
+          }
           pVar = &utf8;
         }
 #endif