Change the VDBE so that all registers are initialized to "Invalid" instead of

NULL and report errors on any attempted read of an Invalid register.  This
will help prevent future bugs similar to [7bbfb7d442].

FossilOrigin-Name: 0064bab77149768640d7758a3e271d5a1d63b256

diff --cc manifest
index 9b3f6a87001e3f23195f22dcb721557a94542f99,84cc79d6f6b4615cf8d143fd6d9a26626cfea25a..a364c55cdf3c5164490799f074ce1a162cfd059d
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Modify\sthe\sOP_Once\sopcode\sso\sthat\sit\sworks\scorrectly\sin\strigger\ssub-programs.\sThis\sis\sa\scandidate\sfix\sfor\s[7bbfb7d442].
- D 2011-12-09T13:24:16.480
 -C Remove\san\sunnecessary\scondition.
 -D 2011-12-09T17:51:30.877
++C Change\sthe\sVDBE\sso\sthat\sall\sregisters\sare\sinitialized\sto\s"Invalid"\sinstead\sof\nNULL\sand\sreport\serrors\son\sany\sattempted\sread\sof\san\sInvalid\sregister.\s\sThis\nwill\shelp\sprevent\sfuture\sbugs\ssimilar\sto\s[7bbfb7d442].
++D 2011-12-09T18:06:44.319
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in 5b4a3e12a850b021547e43daf886b25133b44c07
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -243,7 -243,7 +243,7 @@@ F src/vdbe.c 029add0c5197a61db588824a58
  F src/vdbe.h 18f581cac1f4339ec3299f3e0cc6e11aec654cdb
  F src/vdbeInt.h 23a9506c9ab31e7823d7257d1828d2d7843443a0
  F src/vdbeapi.c 86189ebba2c49791d75eaa12929f3ce6527596bd
- F src/vdbeaux.c cdd74a86c6281b4393c5f94d8f5e40e160e44e19
 -F src/vdbeaux.c ff5eefb43647e1b1e60c1c23407523dbcfd0a86c
++F src/vdbeaux.c 71a0cd6ae14ddb2e2a6d6b97d5b54ae753272682
  F src/vdbeblob.c 32f2a4899d67f69634ea4dd93e3f651936d732cb
  F src/vdbemem.c 2fc78b3e0fabcc1eaa23cd79dd2e30e6dcfe1e56
  F src/vdbesort.c 468d43c057063e54da4f1988b38b4f46d60e7790
@@@ -978,7 -978,7 +978,7 @@@ F tool/tostr.awk e75472c2f98dd76e06b8c9
  F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
  F tool/warnings-clang.sh 9f406d66e750e8ac031c63a9ef3248aaa347ef2a
  F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
- P 3702a31e56fe02d14ce246109b318a124cad9f1a
- R 212172c6a4e482305cc0a6c8ccb724d1
- U dan
- Z fd67074fb89c049640d6ea2f96341088
 -P 421714dad32f3460fa40a7f65e9fa276f5e37f58
 -R d509edfce30feab29fb6f6730ef15f2e
++P 557c69055a300b4082830b5f4803091dca1c3140 d9ba023c608bce7768bc08478f9df9243f2e73ce
++R c86cf051b4407cf6125edf9f0e3046a6
+ U drh
 -Z 197b12cf9381c9c365def8e131bb26a7
++Z b55d92759eb01feac738f44135c5de26

diff --cc manifest.uuid
index ae75c089600cbb0f7fddc44ad76b726cda0eef8a,1c1bcc40a50afceeac1233faf08c688876fb7a1c..2ddca39cd51428b38bb877c4cd59c7bc097096dc
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 557c69055a300b4082830b5f4803091dca1c3140
 -d9ba023c608bce7768bc08478f9df9243f2e73ce
++0064bab77149768640d7758a3e271d5a1d63b256

diff --cc src/vdbeaux.c
index b6e13f1335ccd4bcb8c643c34ee9b5265d7c26e7,c8f6911ae1ebcd48ba4724f0ae438f290ee5b2ab..8b085ea6ce3231e4cb3287fac6deef986b1a7f76
--- 1/src/vdbeaux.c
--- 2/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@@ -2135,6 -2136,7 +2136,7 @@@ int sqlite3VdbeHalt(Vdbe *p)
    if( p->db->mallocFailed ){
      p->rc = SQLITE_NOMEM;
    }
 -  memset(p->aOnceFlag, 0, p->nOnceFlag);
++  if( p->aOnceFlag ) memset(p->aOnceFlag, 0, p->nOnceFlag);
    closeAllCursors(p);
    if( p->magic!=VDBE_MAGIC_RUN ){
      return SQLITE_OK;