In the Win32 VFS, when truncating a file, unmap it first.

FossilOrigin-Name: 21510a66dce4d0843ccfe20f092a01f5a52563ef244a94f1d5d2563305cab925

3 files changed, 54 insertions, 11 deletions

diff --git a/src/os_win.c b/src/os_win.c
index 3eb2f3c61..2a4b613ff 100644
--- a/src/os_win.c
+++ b/src/os_win.c
@@ -2904,6 +2904,9 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   winFile *pFile = (winFile*)id;  /* File handle object */
   int rc = SQLITE_OK;             /* Return code for this function */
   DWORD lastErrno;
+#if SQLITE_MAX_MMAP_SIZE>0
+  sqlite3_int64 oldMmapSize;
+#endif
 
   assert( pFile );
   SimulateIOError(return SQLITE_IOERR_TRUNCATE);
@@ -2919,6 +2922,15 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
     nByte = ((nByte + pFile->szChunk - 1)/pFile->szChunk) * pFile->szChunk;
   }
 
+#if SQLITE_MAX_MMAP_SIZE>0
+  if( pFile->pMapRegion ){
+    oldMmapSize = pFile->mmapSize;
+  }else{
+    oldMmapSize = 0;
+  }
+  winUnmapfile(pFile);
+#endif
+
   /* SetEndOfFile() returns non-zero when successful, or zero when it fails. */
   if( winSeekFile(pFile, nByte) ){
     rc = winLogError(SQLITE_IOERR_TRUNCATE, pFile->lastErrno,
@@ -2931,12 +2943,12 @@ static int winTruncate(sqlite3_file *id, sqlite3_int64 nByte){
   }
 
 #if SQLITE_MAX_MMAP_SIZE>0
-  /* If the file was truncated to a size smaller than the currently
-  ** mapped region, reduce the effective mapping size as well. SQLite will
-  ** use read() and write() to access data beyond this point from now on.
-  */
-  if( pFile->pMapRegion && nByte<pFile->mmapSize ){
-    pFile->mmapSize = nByte;
+  if( rc==SQLITE_OK && oldMmapSize>0 ){
+    if( oldMmapSize>nByte ){
+      winMapfile(pFile, -1);
+    }else{
+      winMapfile(pFile, oldMmapSize);
+    }
   }
 #endif
 
diff --git a/src/shell.c.in b/src/shell.c.in
index ab1ec6af7..59ea6aac0 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -79,12 +79,15 @@ typedef unsigned char u8;
 #if (!defined(_WIN32) && !defined(WIN32)) || defined(__MINGW32__)
 # include <unistd.h>
 # include <dirent.h>
+# define GETPID getpid
 # if defined(__MINGW32__)
 #  define DIRENT dirent
 #  ifndef S_ISLNK
 #   define S_ISLNK(mode) (0)
 #  endif
 # endif
+#else
+# define GETPID (int)GetCurrentProcessId
 #endif
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -8348,6 +8351,23 @@ int SQLITE_CDECL wmain(int argc, wchar_t **wargv){
   stdin_is_interactive = isatty(0);
   stdout_is_console = isatty(1);
 
+#if !defined(_WIN32_WCE)
+  if( getenv("SQLITE_DEBUG_BREAK") ){
+    if( isatty(0) && isatty(2) ){
+      fprintf(stderr,
+          "attach debugger to process %d and press any key to continue.\n",
+          GETPID());
+      fgetc(stdin);
+    }else{
+#if defined(_WIN32) || defined(WIN32)
+      DebugBreak();
+#elif defined(SIGTRAP)
+      raise(SIGTRAP);
+#endif
+    }
+  }
+#endif
+
 #if USE_SYSTEM_SQLITE+0!=1
   if( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,60)!=0 ){
     utf8_printf(stderr, "SQLite header and source version mismatch\n%s\n%s\n",
diff --git a/src/tclsqlite.c b/src/tclsqlite.c
index e5984ec80..d0b4634d4 100644
--- a/src/tclsqlite.c
+++ b/src/tclsqlite.c
@@ -60,6 +60,7 @@
 
 /* Used to get the current process ID */
 #if !defined(_WIN32)
+# include <signal.h>
 # include <unistd.h>
 # define GETPID getpid
 #elif !defined(_WIN32_WCE)
@@ -69,6 +70,8 @@
 #  endif
 #  include <windows.h>
 # endif
+# include <io.h>
+# define isatty(h) _isatty(h)
 # define GETPID (int)GetCurrentProcessId
 #endif
 
@@ -3733,11 +3736,19 @@ int SQLITE_CDECL TCLSH_MAIN(int argc, char **argv){
 #endif
 
 #if !defined(_WIN32_WCE)
-  if( getenv("BREAK") ){
-    fprintf(stderr,
-        "attach debugger to process %d and press any key to continue.\n",
-        GETPID());
-    fgetc(stdin);
+  if( getenv("SQLITE_DEBUG_BREAK") ){
+    if( isatty(0) && isatty(2) ){
+      fprintf(stderr,
+          "attach debugger to process %d and press any key to continue.\n",
+          GETPID());
+      fgetc(stdin);
+    }else{
+#if defined(_WIN32) || defined(WIN32)
+      DebugBreak();
+#elif defined(SIGTRAP)
+      raise(SIGTRAP);
+#endif
+    }
   }
 #endif