_TranslateType() now falls back to the preferred app of the super type in

case the preferred app of the type itself is not available or valid.
Ie. if you have deleted an application that was the preferred app for
"image/png", the system will now try to open the file with the preferred
app for "image".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16565 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kits/app/Roster.cpp

@@ -2120,25 +2120,50 @@ BRoster::_TranslateType(const char *mimeType, BMimeType *appMeta,
 	status_t error = type.SetTo(mimeType);
 
 	// get the preferred app
-	char appSignature[B_MIME_TYPE_LENGTH];
+	char primarySignature[B_MIME_TYPE_LENGTH];
+	char secondarySignature[B_MIME_TYPE_LENGTH];
+	primarySignature[0] = '\0';
+	secondarySignature[0] = '\0';
+
 	if (error == B_OK) {
 		if (type.IsInstalled()) {
 			BMimeType superType;
-			if (type.GetPreferredApp(appSignature) != B_OK
+			if (type.GetSupertype(&superType) == B_OK)
-				&& (type.GetSupertype(&superType) != B_OK
+				superType.GetPreferredApp(secondarySignature);
-					|| superType.GetPreferredApp(appSignature) != B_OK)) {
+
+			if (type.GetPreferredApp(primarySignature) != B_OK
+				&& !primarySignature[0]) {
 				// The type is installed, but has no preferred app.
 				// In fact it might be an app signature and even having a
 				// valid app hint. Nevertheless we fail.
 				error = B_LAUNCH_FAILED_NO_PREFERRED_APP;
+			} else if (!strcmp(primarySignature, secondarySignature)) {
+				// Both types have the same preferred app, there is
+				// no point in testing it twice.
+				secondarySignature[0] = '\0';
 			}
 		} else {
 			// The type is not installed. We assume it is an app signature.
-			strcpy(appSignature, mimeType);
+			strcpy(primarySignature, mimeType);
 		}
 	}
-	if (error == B_OK)
+
-		error = appMeta->SetTo(appSignature);
+	if (error != B_OK)
+		return error;
+
+	// see if we can find the application and if it's valid, try
+	// both preferred app signatures, if available (from type and
+	// super type)
+
+	status_t primaryError = B_OK;
+
+	for (int32 tries = 0; tries < 2; tries++) {
+		const char* signature = tries == 0 ? primarySignature : secondarySignature;
+		if (signature[0] == '\0')
+			continue;
+
+		error = appMeta->SetTo(signature);
+
 		// check, whether the signature is installed and has an app hint
 		bool appFound = false;
 		if (error == B_OK && appMeta->GetAppHint(appRef) == B_OK) {
@@ -2160,6 +2185,16 @@ BRoster::_TranslateType(const char *mimeType, BMimeType *appMeta,
 		// check, whether the app can be used
 		if (error == B_OK)
 			error = can_app_be_used(appRef);
+
+		if (error != B_OK) {
+			if (tries == 0)
+				primaryError = error;
+			else if (primarySignature[0])
+				error = primaryError;
+		} else
+			break;
+	}
+
 	return error;
 }