(svn r2775) Deleting a file can fail, display an error message when it happens

hal.h

@@ -87,7 +87,7 @@ char *FiosBrowseTo(const FiosItem *item);
 // Return path, free space and stringID
 StringID FiosGetDescText(const char **path, uint32 *tot);
 // Delete a name
-void FiosDelete(const char *name);
+bool FiosDelete(const char *name);
 // Make a filename from a name
 void FiosMakeSavegameName(char *buf, const char *name);
 

misc_gui.c

@@ -1328,7 +1328,9 @@ static void SaveLoadDlgWndProc(Window *w, WindowEvent *e)
 		break;
 	case WE_TIMEOUT:
 		if (HASBIT(w->click_state, 10)) { /* Delete button clicked */
-			FiosDelete(WP(w,querystr_d).text.buf);
+			if (!FiosDelete(WP(w,querystr_d).text.buf)) {
+				ShowErrorMessage(INVALID_STRING_ID, STR_4008_UNABLE_TO_DELETE_FILE, 0, 0);
+			}
 			SetWindowDirty(w);
 			BuildFileList();
 			if (_saveload_mode == SLD_SAVE_GAME) {

os2.c

@@ -415,12 +415,12 @@ void FiosMakeSavegameName(char *buf, const char *name)
 	sprintf(buf, "%s\\%s%s", _fios_path, name, extension);
 }
 
-void FiosDelete(const char *name)
+bool FiosDelete(const char *name)
 {
 	char path[512];
 
 	snprintf(path, lengthof(path), "%s\\%s", _fios_path, name);
-	unlink(path);
+	return unlink(path) == 0;
 }
 
 bool FileExists(const char *filename)

unix.c

@@ -353,12 +353,12 @@ void FiosMakeSavegameName(char *buf, const char *name)
 	sprintf(buf, "%s/%s%s", _fios_path, name, extension);
 }
 
-void FiosDelete(const char *name)
+bool FiosDelete(const char *name)
 {
 	char path[512];
 
 	snprintf(path, lengthof(path), "%s/%s", _fios_path, name);
-	unlink(path);
+	return unlink(path) == 0;
 }
 
 bool FileExists(const char *filename)

win32.c

@@ -911,12 +911,12 @@ void FiosMakeSavegameName(char *buf, const char *name)
 	sprintf(buf, "%s\\%s%s", _fios_path, name, extension);
 }
 
-void FiosDelete(const char *name)
+bool FiosDelete(const char *name)
 {
 	char path[512];
 
 	snprintf(path, lengthof(path), "%s\\%s", _fios_path, name);
-	DeleteFile(path);
+	return DeleteFile(path) != 0;
 }
 
 bool FileExists(const char *filename)