Get fault injection for testing working correctly. Other code clean-up.

FossilOrigin-Name: ff492277ed00c1f637a5b4ccd6d8193ea22f6781f90073861588a2b7d5c045b7

manifest

@@ -1,5 +1,5 @@
-C Minor\sstyle\schanges\sto\sthe\sprevious\sMSVC\smakefile\schanges\son\sthis\sbranch.
-D 2023-07-10T19:21:09.466
+C Get\sfault\sinjection\sfor\stesting\sworking\scorrectly.\s\sOther\scode\sclean-up.
+D 2023-07-11T15:52:52.116
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -719,7 +719,7 @@ F src/vdbetrace.c fe0bc29ebd4e02c8bc5c1945f1d2e6be5927ec12c06d89b03ef2a4def34bf8
 F src/vdbevtab.c aae4bd769410eb7e1d02c42613eec961d514459b1c3c1c63cfc84e92a137daac
 F src/vtab.c 1ecf8c3745d29275688d583e12822fa984d421e0286b5ef50c137bc3bf6d7a64
 F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
-F src/wal.c b4668b94644c79bd9e44ba0aacaeb32631413d1ccee72e67606443a30cc6e56e
+F src/wal.c e4bfb243cc1f6f89c7fba5dd8872ae38a8c1dcc760c276dbb164edb7290072a6
 F src/wal.h 04a9e53121d5076f2a173b0f2facb39d33047093fee71bd3bbe6b1f6f1f5fd4b
 F src/walker.c 7c7ea0115345851c3da4e04e2e239a29983b61fb5b038b94eede6aba462640e2
 F src/where.c 2dc708cf8b6a691fb79f16bbc46567497ee6f991043318d421e294b2da114d93
@@ -2044,8 +2044,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 0e67a82f6cfe681d4676ac5c92d92e95b9dcc3198df21516bccdde002f5e52ae
-R 2485a85a908a05b5fd0644b2f7fd3722
-U mistachkin
-Z 5b8cb43f82a279de421ae118ca8d7765
+P 4c950872c870a5968fa4cb8840cf60569a66c0e508811ee79992825ec9c02da3
+R 966aa4944515db815a2a3b1d2b09adbd
+U drh
+Z 4e4c72cb034026cb3cf7caeaeea5ca69
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-4c950872c870a5968fa4cb8840cf60569a66c0e508811ee79992825ec9c02da3
+ff492277ed00c1f637a5b4ccd6d8193ea22f6781f90073861588a2b7d5c045b7

src/wal.c

@@ -528,15 +528,13 @@ struct Wal {
   u32 iReCksum;              /* On commit, recalculate checksums from here */
   const char *zWalName;      /* Name of WAL file */
   u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
-# ifdef SQLITE_DEBUG
-  int nSehTry;               /* Number of nested SEH_TRY{} blocks */
-# endif
 #ifdef SQLITE_USE_SEH
   u32 lockMask;              /* Mask of locks held */
   void *pFree;               /* Pointer to sqlite3_free() if exception thrown */
   int iSysErrno;             /* System error code following exception */
 #endif
 #ifdef SQLITE_DEBUG
+  int nSehTry;               /* Number of nested SEH_TRY{} blocks */
   u8 lockError;              /* True if a locking error has occurred */
 #endif
 #ifdef SQLITE_ENABLE_SNAPSHOT
@@ -618,19 +616,32 @@ struct WalIterator {
     sizeof(ht_slot)*HASHTABLE_NSLOT + HASHTABLE_NPAGE*sizeof(u32) \
 )
 
+/*
+** Structured Exception Handling (SEH) is a Windows-specific technique
+** for catching exceptions raised while accessing memory-mapped files.
+**
+** The -DSQLITE_USE_SEH compile-time option means to use SEH to catch and
+** deal with system-level errors that arise during WAL -shm file processing.
+** Without this compile-time option, any system-level faults that appear
+** while accessing the memory-mapped -shm file will cause a process-wide
+** signal to be deliver, which will more than likely cause the entire
+** process to exit.
+*/
 #ifdef SQLITE_USE_SEH
-
 #include <Windows.h>
 
+/* Beginning of a block of code in which an exception might occur */
 # define SEH_TRY    __try { \
    assert( walAssertLockmask(pWal) && pWal->nSehTry==0 ); \
    VVA_ONLY(pWal->nSehTry++);
 
+/* The end of a block of code in which an exception might occur */
 # define SEH_EXCEPT(X) \
    VVA_ONLY(pWal->nSehTry--); \
    assert( pWal->nSehTry==0 ); \
    } __except( sehExceptionFilter(pWal, GetExceptionCode(), GetExceptionInformation() ) ){ X }
 
+/* Simulate a memory-mapping fault in the -shm file for testing purposes */
 # define SEH_INJECT_FAULT sehInjectFault(pWal) 
 
 /*
@@ -662,10 +673,10 @@ static void sehInjectFault(Wal *pWal){
 
   res = sqlite3FaultSim(650);
   if( res!=0 ){
-    ULONG aArg[3];
+    ULONG_PTR aArg[3];
     aArg[0] = 0;
     aArg[1] = 0;
-    aArg[2] = (ULONG)res;
+    aArg[2] = (ULONG_PTR)res;
     RaiseException(EXCEPTION_IN_PAGE_ERROR, 0, 3, (const ULONG_PTR*)aArg);
   }
 }