Avoid segfaulting on an incremental blob write if SQLITE_ENABLE_PREUPDATE_HOOK

set but no pre-update hooks are defined.

FossilOrigin-Name: 62c446340475b52b843c0345eda32ebe86fa9159

manifest

@@ -1,5 +1,5 @@
-C Fix\serrors\sin\sa\scomment\sin\ssqlite3session.c.\sNo\schanges\sto\scode.
-D 2011-07-26T17:53:53.311
+C Avoid\ssegfaulting\son\san\sincremental\sblob\swrite\sif\sSQLITE_ENABLE_PREUPDATE_HOOK\nset\sbut\sno\spre-update\shooks\sare\sdefined.
+D 2011-08-03T21:32:11.649
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 1e6988b3c11dee9bd5edc0c804bd4468d74a9cdc
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -255,7 +255,7 @@ F src/vdbe.h 322af148cceef120bb1ec9cff7f122e76abf94da
 F src/vdbeInt.h 3de6588b36c833969aebab202e1766d586c37ec2
 F src/vdbeapi.c ddd061183e2c3015f676e53ee85fcaf306617e8e
 F src/vdbeaux.c 7d0b75a04ac466d25a90fefd1df83361a2ab0ad7
-F src/vdbeblob.c a547f286b651641bdb43a567af66d0e776a39ea2
+F src/vdbeblob.c fde0374afb0c512614aed191ac2683f6772d2b8f
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 901791a47318c0562cd0c676a2c6ff1bc530e582
@@ -965,7 +965,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
 F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 2ebae31e1eb352696f3c2f7706a34c084b28c262
-P dc6ecacd7724089a0387e69a0fd5cdbfdd2023f8
-R 243487bed84c57b1cd5a32970f8d4775
-U dan
-Z 2c93411bbe8d90a5b2b924f24cbf2370
+P d5f4c4c0bf0d488db11c6ab0d26ca3554a57d0ff
+R dc4862fa4ca184e0298413704bde1899
+U drh
+Z abe606476a76771b05a5d0a0f3902dc5

manifest.uuid

@@ -1 +1 @@
-d5f4c4c0bf0d488db11c6ab0d26ca3554a57d0ff
+62c446340475b52b843c0345eda32ebe86fa9159

src/vdbeblob.c

@@ -392,7 +392,7 @@ static int blobReadWrite(
     sqlite3BtreeEnterCursor(p->pCsr);
 
 #ifdef SQLITE_ENABLE_PREUPDATE_HOOK
-    if( xCall==sqlite3BtreePutData ){
+    if( xCall==sqlite3BtreePutData && db->xPreUpdateCallback ){
       /* If a pre-update hook is registered and this is a write cursor, 
       ** invoke it here. 
       **