Improved VDBE comments on the constraint checker. Fix a missing write

lock in the UPDATE logic.

FossilOrigin-Name: 3bed599e74d354bf1513e4fb0e8665376ba44d0b

manifest

@@ -1,5 +1,5 @@
-C Some\sUPDATE\sstatements\snow\sworking\sin\sWITHOUT\sROWID\stables.
-D 2013-11-01T12:42:21.731
+C Improved\sVDBE\scomments\son\sthe\sconstraint\schecker.\s\sFix\sa\smissing\swrite\nlock\sin\sthe\sUPDATE\slogic.
+D 2013-11-01T14:03:20.023
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 0522b53cdc1fcfc18f3a98e0246add129136c654
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -182,7 +182,7 @@ F src/global.c 5caf4deab621abb45b4c607aad1bd21c20aac759
 F src/hash.c ac3470bbf1ca4ae4e306a8ecb0fdf1731810ffe4
 F src/hash.h 8890a25af81fb85a9ad7790d32eedab4b994da22
 F src/hwtime.h d32741c8f4df852c7d959236615444e2b1063b08
-F src/insert.c c04429bde588ba7f5e90dc14bbe31d25334c1b75
+F src/insert.c da74aded06680ff30a87065df70fda16af3ecda3
 F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d
 F src/legacy.c 0df0b1550b9cc1f58229644735e317ac89131f12
 F src/lempar.c cdf0a000315332fc9b50b62f3b5e22e080a0952b
@@ -275,7 +275,7 @@ F src/test_vfstrace.c 34b544e80ba7fb77be15395a609c669df2e660a2
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/tokenize.c 70061085a51f2f4fc15ece94f32c03bcb78e63b2
 F src/trigger.c 53d6b5d50b3b23d4fcd0a36504feb5cff9aed716
-F src/update.c fe12f3cd782804d8df8aa327900584d664bf902e
+F src/update.c fff9ac57e36e54ac939e22aac077326224759372
 F src/utf.c 6fc6c88d50448c469c5c196acf21617a24f90269
 F src/util.c 2fa6c821d28bbdbeec1b2a7b091a281c9ef8f918
 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
@@ -1128,7 +1128,7 @@ F tool/vdbe-compress.tcl f12c884766bd14277f4fcedcae07078011717381
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P cdf00248cf8f7e3c2a3f2f5514273fbacc6fc8d9
-R 0a34f0b854a101e697f3642e97bf3e47
+P 5c0eaea6a26b5c3310d96b3c896ac3068a3ebad1
+R 91e4e19c708f99c7ec09052b49466395
 U drh
-Z cabf904a24b1591bbac5208c61b221d3
+Z 7a82973f52b628c87c749d18c8301e86

manifest.uuid

@@ -1 +1 @@
-5c0eaea6a26b5c3310d96b3c896ac3068a3ebad1
+3bed599e74d354bf1513e4fb0e8665376ba44d0b

src/insert.c

@@ -1435,12 +1435,14 @@ void sqlite3GenerateConstraintChecks(
     regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn);
     for(i=0; i<pIdx->nColumn; i++){
       int iField = pIdx->aiColumn[i];
+      int x;
       if( iField<0 || iField==pTab->iPKey ){
-        iField = regNewData;
+        x = regNewData;
       }else{
-        iField += regNewData + 1;
+        x = iField + regNewData + 1;
       }
-      sqlite3VdbeAddOp2(v, OP_SCopy, iField, regIdx+i);
+      sqlite3VdbeAddOp2(v, OP_SCopy, x, regIdx+i);
+      VdbeComment((v, "%s", iField<0 ? "rowid" : pTab->aCol[iField].zName));
     }
     sqlite3VdbeAddOp3(v, OP_MakeRecord, regIdx, pIdx->nColumn, aRegIdx[ix]);
     sqlite3VdbeChangeP4(v, -1, sqlite3IndexAffinityStr(v, pIdx), P4_TRANSIENT);

src/update.c

@@ -387,6 +387,7 @@ void sqlite3Update(
     if( !okOnePass && HasRowid(pTab) ){
       sqlite3OpenTable(pParse, iDataCur, iDb, pTab, OP_OpenWrite); 
     }
+    sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);
     if( onError==OE_Replace ){
       openAll = 1;
     }else{