add several safety/consistency and UI improvements

HashCheck will never save a partially complete checksum file:
 * canceling an in-progress save causes the checksum file to be deleted
 * the Save button on file properties is unavailable if Stop is pressed

File read errors are now more visible:
 * in a checksum file, they are included as all 0's so that verify fails
 * on file properties they are included as all X's to stand out

When selected hashes in Options change, the tab is updated immediately:
 * any hashes which have already been calculated are not recalculated

Saving checksum files with an unselected hash from file properties works

HashCalc.c

@@ -44,7 +44,7 @@ __forceinline VOID WINAPI HashCalcSetSavePrefix( PHASHCALCCONTEXT phcctx, PTSTR
 	Path processing
 \*============================================================================*/
 
-VOID WINAPI HashCalcPrepare( PHASHCALCCONTEXT phcctx )
+BOOL WINAPI HashCalcPrepare( PHASHCALCCONTEXT phcctx )
 {
 	PTSTR pszPrev = NULL;
 	PTSTR pszCurrent, pszCurrentEnd;
@@ -128,7 +128,7 @@ VOID WINAPI HashCalcPrepare( PHASHCALCCONTEXT phcctx )
 
 				if (pItem)
 				{
-					pItem->bValid = FALSE;
+                    pItem->results.dwFlags = 0;
 					pItem->cchPath = cchCurrent;
 					memcpy(pItem->szPath, pszCurrent, cbCurrent);
 
@@ -143,10 +143,11 @@ VOID WINAPI HashCalcPrepare( PHASHCALCCONTEXT phcctx )
         if (phcctx->status == PAUSED)
             WaitForSingleObject(phcctx->hUnpauseEvent, INFINITE);
         if (phcctx->status == CANCEL_REQUESTED)
-			return;
+			return(FALSE);
 
 		pszPrev = pszCurrent;
 	}
+    return(TRUE);
 }
 
 VOID WINAPI HashCalcWalkDirectory( PHASHCALCCONTEXT phcctx, PTSTR pszPath, UINT cchPath )
@@ -192,7 +193,7 @@ VOID WINAPI HashCalcWalkDirectory( PHASHCALCCONTEXT phcctx, PTSTR pszPath, UINT
 
 				if (pItem)
 				{
-					pItem->bValid = FALSE;
+                    pItem->results.dwFlags = 0;
 					pItem->cchPath = cchNew;
 					memcpy(pItem->szPath, pszPath, cbPathBuffer);
 
@@ -300,8 +301,6 @@ VOID WINAPI HashCalcInitSave( PHASHCALCCONTEXT phcctx )
 	     phcctx->ofn.nFilterIndex &&
 		 phcctx->ofn.nFilterIndex <= NUM_HASHES)
 	{
-		BOOL bSuccess = FALSE;
-
 		// Save the filter in the user's preferences
 		if (phcctx->opt.dwFilterIndex != phcctx->ofn.nFilterIndex)
 		{
@@ -330,7 +329,7 @@ VOID WINAPI HashCalcInitSave( PHASHCALCCONTEXT phcctx )
 		// Open the file for output
 		phcctx->hFileOut = CreateFile(
 			pszFile,
-			FILE_APPEND_DATA,
+			FILE_APPEND_DATA | DELETE,
 			FILE_SHARE_READ,
 			NULL,
 			CREATE_ALWAYS,
@@ -385,19 +384,32 @@ VOID WINAPI HashCalcSetSaveFormat( PHASHCALCCONTEXT phcctx )
 
 BOOL WINAPI HashCalcWriteResult( PHASHCALCCONTEXT phcctx, PHASHCALCITEM pItem )
 {
-	PCTSTR pszHash;
-    WCHAR szWbuffer[MAX_PATH_BUFFER];
-    CHAR  szAbuffer[MAX_PATH_BUFFER];
+	PCTSTR pszHash;                     // will be pointed to the hash name
+    WCHAR szWbuffer[MAX_PATH_BUFFER];   // wide-char buffer
+    CHAR  szAbuffer[MAX_PATH_BUFFER];   // narrow-char buffer
 #ifdef UNICODE
 #   define szTbuffer szWbuffer
 #else
 #   define szTbuffer szAbuffer
 #endif
-	PVOID pvLine;            // Will be pointed to the buffer to write out
-	size_t cchLine, cbLine;  // Length of line, in TCHARs or BYTEs, EXCLUDING the terminator
-
-	if (!pItem->bValid)
-		return(FALSE);
+    PTSTR szTbufferAppend = szTbuffer;  // current end of the buffer used to build output
+    size_t cchLine = MAX_PATH_BUFFER;   // starts off as count of remaining TCHARS in the buffer
+    PVOID pvLine;                       // will be pointed to the buffer to write out
+    size_t cbLine;                      // will be line length in bytes, EXCLUDING nul terminator
+    BOOL bRetval = TRUE;
+
+	// If the checksum to save isn't present in the results
+    if (! ((1 << (phcctx->ofn.nFilterIndex - 1)) & pItem->results.dwFlags))
+    {
+        // Start with a commented-out error message - "; UNREADABLE:"
+        WCHAR szUnreadable[MAX_STRINGRES];
+        LoadString(g_hModThisDll, IDS_HV_STATUS_UNREADABLE, szUnreadable, MAX_STRINGRES);
+        StringCchPrintfEx(szTbufferAppend, cchLine, &szTbufferAppend, &cchLine, 0, TEXT("; %s:\r\n"), szUnreadable);
+
+        // We'll still output a hash, but it will be all 0's, that way Verify will indicate an mismatch
+        HashCalcClearInvalid(&pItem->results, TEXT('0'));
+        bRetval = FALSE;
+    }
 
 	// Translate the filter index to a hash
 	switch (phcctx->ofn.nFilterIndex)
@@ -409,19 +421,18 @@ BOOL WINAPI HashCalcWriteResult( PHASHCALCCONTEXT phcctx, PHASHCALCITEM pItem )
 	}
 
 	// Format the line
-	#define HashCalcFormat(a, b) StringCchPrintfEx(szTbuffer, MAX_PATH_BUFFER, NULL, &cchLine, 0, phcctx->szFormat, a, b)
+	#define HashCalcFormat(a, b) StringCchPrintfEx(szTbufferAppend, cchLine, &szTbufferAppend, &cchLine, 0, phcctx->szFormat, a, b)
 	(phcctx->ofn.nFilterIndex == 1) ?
 		HashCalcFormat(pItem->szPath + phcctx->cchAdjusted, pszHash) : // SFV
 		HashCalcFormat(pszHash, pItem->szPath + phcctx->cchAdjusted);  // everything else
 	#undef HashCalcFormat
-	// cchLine is temporarily the count of characters left in the buffer instead of the line length
 
 #ifdef _TIMED
-    StringCchPrintfEx(szTbuffer + (MAX_PATH_BUFFER-cchLine), cchLine, NULL, &cchLine, 0,
+    StringCchPrintfEx(szTbufferAppend, cchLine, NULL, &cchLine, 0,
                       _T("; Elapsed: %d ms\r\n"), pItem->dwElapsed);
 #endif
 
-	cchLine = MAX_PATH_BUFFER - cchLine;  // now it's back to being the line length
+	cchLine = MAX_PATH_BUFFER - cchLine;  // from now on cchLine is the line length in bytes, EXCLUDING nul terminator
 	if (cchLine > 0)
 	{
 		// Convert to the correct encoding
@@ -479,7 +490,45 @@ BOOL WINAPI HashCalcWriteResult( PHASHCALCCONTEXT phcctx, PHASHCALCITEM pItem )
 	}
 	else return(FALSE);
 
-	return(TRUE);
+	return(bRetval);
+}
+
+VOID WINAPI HashCalcClearInvalid( PWHRESULTEX pwhres, WCHAR cInvalid )
+{
+#ifdef UNICODE
+#   define _tmemset wmemset
+#else
+#   define _tmemset memset
+#endif
+
+#define HASH_CLEAR_INVALID_op(alg)                                                \
+    if (! (pwhres->dwFlags & WHEX_CHECK##alg))                                    \
+    {                                                                             \
+        _tmemset(pwhres->szHex##alg, cInvalid, countof(pwhres->szHex##alg) - 1);  \
+        pwhres->szHex##alg[countof(pwhres->szHex##alg) - 1] = L'\0';              \
+    }
+    FOR_EACH_HASH(HASH_CLEAR_INVALID_op)
+}
+
+// This can only succeed on Windows Vista and later;
+// returns FALSE on failure
+BOOL WINAPI HashCalcDeleteFileByHandle(HANDLE hFile)
+{
+    if (hFile == INVALID_HANDLE_VALUE)
+        return(FALSE);
+
+    HMODULE hKernel32 = GetModuleHandle(TEXT("kernel32.dll"));
+    if (hKernel32 == NULL)
+        return(FALSE);
+
+    typedef BOOL(WINAPI* PFN_SFIBH)(_In_ HANDLE, _In_ FILE_INFO_BY_HANDLE_CLASS, _In_ LPVOID, _In_ DWORD);
+    PFN_SFIBH pfnSetFileInformationByHandle = (PFN_SFIBH)GetProcAddress(hKernel32, "SetFileInformationByHandle");
+    if (pfnSetFileInformationByHandle == NULL)
+        return(FALSE);
+
+    FILE_DISPOSITION_INFO fdi;
+    fdi.DeleteFile = TRUE;
+    return(pfnSetFileInformationByHandle(hFile, FileDispositionInfo, &fdi, sizeof(fdi)));
 }
 
 VOID WINAPI HashCalcSetSavePrefix( PHASHCALCCONTEXT phcctx, PTSTR pszSave )

HashCalc.h

@@ -90,7 +90,6 @@ typedef struct {
 
 // Per-file data
 typedef struct {
-	BOOL bValid;                     // FALSE if the file could not be opened
 	UINT cchPath;                    // length of path in characters, not including NULL
 	WHRESULTEX results;              // hash results
 #ifdef _TIMED
@@ -101,10 +100,12 @@ typedef struct {
 } HASHCALCITEM, *PHASHCALCITEM;
 
 // Public functions
-VOID WINAPI HashCalcPrepare( PHASHCALCCONTEXT phcctx );
+BOOL WINAPI HashCalcPrepare( PHASHCALCCONTEXT phcctx );
 VOID WINAPI HashCalcInitSave( PHASHCALCCONTEXT phcctx );
 VOID WINAPI HashCalcSetSaveFormat( PHASHCALCCONTEXT phcctx );
 BOOL WINAPI HashCalcWriteResult( PHASHCALCCONTEXT phcctx, PHASHCALCITEM pItem );
+VOID WINAPI HashCalcClearInvalid( PWHRESULTEX pwhres, WCHAR cInvalid );
+BOOL WINAPI HashCalcDeleteFileByHandle( HANDLE hFile );
 VOID WINAPI HashCalcTogglePrep( PHASHCALCCONTEXT phcctx, BOOL bState );
 
 #ifdef __cplusplus

HashCheck.rc

@@ -128,7 +128,7 @@ IDD_OPTIONS  DIALOGEX 10, 10, 200, 264
     AUTORADIOBUTTON "", IDC_OPT_ENCODING_UTF16, 13,  99, 174, 10
     AUTORADIOBUTTON "", IDC_OPT_ENCODING_ANSI,  13, 113, 174, 10
     GROUPBOX        "", IDC_OPT_CHK,             7, 137, 186, 58, WS_GROUP
-    AUTOCHECKBOX  "CRC-32",IDC_OPT_CHK_CRC32,   13, 150,  54, 10, WS_TABSTOP
+    AUTOCHECKBOX "C&RC-32",IDC_OPT_CHK_CRC32,   13, 150,  54, 10, WS_TABSTOP
     AUTOCHECKBOX     "MD5",IDC_OPT_CHK_MD5,     13, 164,  54, 10, WS_TABSTOP
     AUTOCHECKBOX   "SHA-1",IDC_OPT_CHK_SHA1,    13, 178,  54, 10, WS_TABSTOP
     AUTOCHECKBOX "SHA-256",IDC_OPT_CHK_SHA256, 100, 150,  54, 10, WS_TABSTOP

HashCheckCommon.c

@@ -28,6 +28,8 @@ HANDLE __fastcall CreateThreadCRT( PVOID pThreadProc, PVOID pvParam )
 		pcmnctx->cHandledMsgs = 0;
 		pcmnctx->hWndPBTotal = GetDlgItem(pcmnctx->hWnd, IDC_PROG_TOTAL);
 		pcmnctx->hWndPBFile = GetDlgItem(pcmnctx->hWnd, IDC_PROG_FILE);
+        if (pcmnctx->hUnpauseEvent == NULL)
+            pcmnctx->hUnpauseEvent = CreateEvent(NULL, TRUE, TRUE, NULL);
 		SendMessage(pcmnctx->hWndPBFile, PBM_SETRANGE, 0, MAKELPARAM(0, PROGRESS_BAR_STEPS));
 
 		pThreadProc = WorkerThreadStartup;
@@ -138,7 +140,8 @@ VOID WINAPI SetProgressBarPause( PCOMMONCONTEXT pcmnctx, WPARAM iState )
 		// Vista's progress bar is buggy--if you pause it while it is animating,
 		// the color will not change (but it will stop animating), so it may
 		// be necessary to send another PBM_SETSTATE to get it right
-		SetTimer(pcmnctx->hWnd, TIMER_ID_PAUSE, 750, NULL);
+        if (iState == PBST_PAUSED)
+            SetTimer(pcmnctx->hWnd, TIMER_ID_PAUSE, 750, NULL);
 	}
 }
 
@@ -188,7 +191,7 @@ VOID WINAPI WorkerThreadStop( PCOMMONCONTEXT pcmnctx )
     }
 
 	// Disable the control buttons
-	if (!(pcmnctx->dwFlags & HCF_EXIT_PENDING))
+	if (! (pcmnctx->dwFlags & (HCF_EXIT_PENDING | HCF_RESTARTING)))
 	{
 		EnableWindow(GetDlgItem(pcmnctx->hWnd, IDC_PAUSE), FALSE);
 		EnableWindow(GetDlgItem(pcmnctx->hWnd, IDC_STOP), FALSE);
@@ -203,11 +206,11 @@ VOID WINAPI WorkerThreadCleanup( PCOMMONCONTEXT pcmnctx )
 	// There are only two times this function gets called:
 	// Case 1: The worker thread has exited on its own, and this function
 	// was invoked in response to the thread's exit notification.
-	// Case 2: A forced abort was requested (app exit, system shutdown, etc.),
+	// Case 2: A forced abort was requested (app exit, settings change, etc.),
 	// where this is called right after calling WorkerThreadStop to signal the
 	// thread to exit.
 
-	if (pcmnctx->hThread)
+	if (pcmnctx->hThread != NULL)
 	{
 		if (pcmnctx->status != INACTIVE)
 		{
@@ -220,12 +223,19 @@ VOID WINAPI WorkerThreadCleanup( PCOMMONCONTEXT pcmnctx )
 		}
 
 		CloseHandle(pcmnctx->hThread);
-        CloseHandle(pcmnctx->hUnpauseEvent);
+        pcmnctx->hThread = NULL;
 	}
 
+    // If we're done with the Unpause event and it's open, close it
+    if (!(pcmnctx->dwFlags & HCF_RESTARTING) && pcmnctx->hUnpauseEvent != NULL)
+    {
+        CloseHandle(pcmnctx->hUnpauseEvent);
+        pcmnctx->hUnpauseEvent = NULL;
+    }
+
 	pcmnctx->status = CLEANUP_COMPLETED;
 
-	if (!(pcmnctx->dwFlags & HCF_EXIT_PENDING))
+	if (! (pcmnctx->dwFlags & (HCF_EXIT_PENDING | HCF_RESTARTING)))
 	{
 		static const UINT16 arCtrls[] =
 		{
@@ -244,13 +254,11 @@ VOID WINAPI WorkerThreadCleanup( PCOMMONCONTEXT pcmnctx )
 
 DWORD WINAPI WorkerThreadStartup( PCOMMONCONTEXT pcmnctx )
 {
-    pcmnctx->hUnpauseEvent = CreateEvent(NULL, TRUE, TRUE, NULL);
-
     pcmnctx->pfnWorkerMain(pcmnctx);
 
 	pcmnctx->status = INACTIVE;
 
-	if (!(pcmnctx->dwFlags & HCF_EXIT_PENDING))
+	if (! (pcmnctx->dwFlags & (HCF_EXIT_PENDING | HCF_RESTARTING)))
 		PostMessage(pcmnctx->hWnd, HM_WORKERTHREAD_DONE, (WPARAM)pcmnctx, 0);
 
 	return(0);
@@ -323,7 +331,7 @@ __inline VOID UpdateProgressBar( HWND hWndPBFile, PCRITICAL_SECTION pCritSec,
     }
 }
 
-VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath, PBOOL pbSuccess,
+VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath,
                                   PWHCTXEX pwhctx, PWHRESULTEX pwhres, PBYTE pbuffer,
                                   PFILESIZE pFileSize, LPARAM lParam,
                                   PCRITICAL_SECTION pUpdateCritSec, volatile ULONGLONG* pcbCurrentMaxSize
@@ -334,8 +342,6 @@ VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath, PBOOL
 {
 	HANDLE hFile;
 
-	*pbSuccess = FALSE;
-
 	// If the worker thread is working so fast that the UI cannot catch up,
 	// pause for a bit to let things settle down
 	while (pcmnctx->cSentMsgs > pcmnctx->cHandledMsgs + 50)
@@ -347,6 +353,17 @@ VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath, PBOOL
 			return;
 	}
 
+    // This can happen if a user changes the hash selection in HashProp (if no
+    // new hashes were selected; we still want to run the throttling code above)
+    if (pwhctx->dwFlags == 0)
+    {
+#ifdef _TIMED
+        if (pdwElapsed)
+            *pdwElapsed = 0;
+#endif
+        return;
+    }
+
 	// Indicate that we want lower-case results (TODO: make this an option)
 	pwhctx->uCaseMode = WHFMT_LOWERCASE;
 
@@ -413,8 +430,11 @@ VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath, PBOOL
             if (pdwElapsed)
                 *pdwElapsed = GetTickCount() - dwStarted;
 #endif
-			if (cbFileRead == cbFileSize)
-				*pbSuccess = TRUE;
+            // If we encountered a file read error
+            if (cbFileRead != cbFileSize)
+                // Clear the valid-results bits for the hashes we just calculated
+                // (they are set by WHFinishEx, but they're apparently *not* valid)
+                pwhres->dwFlags &= ~pwhctx->dwFlags;
 
 			if (bUpdateProgress)
 				UpdateProgressBar(pcmnctx->hWndPBFile, pUpdateCritSec, &bCurrentlyUpdating,

HashCheckCommon.h

@@ -35,12 +35,15 @@ extern "C" {
 #define THREAD_SUSPEND_ERROR  ((DWORD)-1)
 #define TIMER_ID_PAUSE        1
 
-// Flags
-#define HCF_EXIT_PENDING      0x0001
-#define HCF_MARQUEE           0x0002
-#define HVF_HAS_SET_TYPE      0x0004
-#define HVF_ITEM_HILITE       0x0008
-#define HPF_HAS_RESIZED       0x0004
+// Flags of DWORD width (which is an unsigned long)
+#define HCF_EXIT_PENDING      0x0001UL
+#define HCF_MARQUEE           0x0002UL
+#define HCF_RESTARTING        0x0004UL
+#define HVF_HAS_SET_TYPE      0x0008UL
+#define HVF_ITEM_HILITE       0x0010UL
+#define HPF_HAS_RESIZED       0x0008UL
+#define HPF_HLIST_PREPPED     0x0010UL
+#define HPF_INTERRUPTED       0x0020UL
 
 // Messages
 #define HM_WORKERTHREAD_DONE        (WM_APP + 0)  // wParam = ctx, lParam = 0
@@ -100,7 +103,7 @@ VOID WINAPI WorkerThreadCleanup( PCOMMONCONTEXT pcmnctx );
 
 // Worker thread functions
 DWORD WINAPI WorkerThreadStartup( PCOMMONCONTEXT pcmnctx );
-VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath, PBOOL pbSuccess,
+VOID WINAPI WorkerThreadHashFile( PCOMMONCONTEXT pcmnctx, PCTSTR pszPath,
                                   PWHCTXEX pwhctx, PWHRESULTEX pwhres, PBYTE pbuffer,
                                   PFILESIZE pFileSize, LPARAM lParam,
                                   PCRITICAL_SECTION pUpdateCritSec, volatile ULONGLONG* pcbCurrentMaxSize

HashCheckTranslations.rc

@@ -229,7 +229,7 @@ STRINGTABLE LANGUAGE LANG_CZECH, SUBLANG_DEFAULT
 	IDS_OPT_TITLE            "HashCheck nastavení"
 	IDS_OPT_CM               "Integrace"
 	IDS_OPT_CM_ALWAYS        "&Zobraz v kontextovém menu"
-	IDS_OPT_CM_EXTENDED      "Zobraz v &rozšířeném kontextovém menu"
+	IDS_OPT_CM_EXTENDED      "Zobraz v rozšířeném &kontextovém menu"
 	IDS_OPT_CM_NEVER         "&Nezobrazuj v kontextovém menu"
 	IDS_OPT_ENCODING         "Znaková sada souboru kontrolního součtu"
 	IDS_OPT_ENCODING_UTF8    "Ulož v U&TF-8"