Clean up AssFile::Load, eliminating some redundant checks, and fixing a few situations where the undo stack could be left in an inconsistant state

Originally committed to SVN as r4785.

aegisub/src/ass_file.cpp

@@ -81,70 +81,53 @@ AssFile::~AssFile() {
 
 /// @brief Load generic subs
 void AssFile::Load(const wxString &_filename,wxString charset,bool addToRecent) {
-	bool ok = false;
-	Clear();
-
 	try {
-		// Try to open file
-		FILE *file;
-#ifdef WIN32
-		file = _tfopen(_filename.c_str(), _T("r"));
-#else
-		file = fopen(_filename.mb_str(*wxConvFileName), "r");
-#endif
-		if (!file) {
-			throw _T("Unable to open file \"") + _filename + _T("\". Check if it exists and if you have permissions to read it.");
-		}
-		fclose(file);
-
-		// Find file encoding
 		if (charset.empty()) {
 			charset = CharSetDetect::GetEncoding(_filename);
 		}
 
-		// Generic preparation
-		Clear();
-
 		// Get proper format reader
 		SubtitleFormat *reader = SubtitleFormat::GetReader(_filename);
 
+		if (!reader) {
+			wxMessageBox(L"Unknown file type","Error loading file",wxICON_ERROR | wxOK);
+			return;
+		}
+
 		// Read file
-		if (reader) {
 		AssFile temp;
 		reader->SetTarget(&temp);
 		reader->ReadFile(_filename,charset);
 		swap(temp);
-			ok = true;
 	}
-
+	catch (agi::UserCancelException const&) {
-		// Couldn't find a type
+		return;
-		else throw _T("Unknown file type.");
 	}
-	catch (agi::UserCancelException const&) { }
 	catch (const wchar_t *except) {
 		wxMessageBox(except,_T("Error loading file"),wxICON_ERROR | wxOK);
+		return;
 	}
 
-	catch (wxString except) {
+	catch (wxString &except) {
 		wxMessageBox(except,_T("Error loading file"),wxICON_ERROR | wxOK);
+		return;
 	}
 
 	// Real exception
 	catch (agi::Exception &e) {
 		wxMessageBox(wxString(e.GetChainedMessage().c_str(), wxConvUTF8), L"Error loading file", wxICON_ERROR|wxOK);
+		return;
 	}
 
 	// Other error
 	catch (...) {
 		wxMessageBox(_T("Unknown error"),_T("Error loading file"),wxICON_ERROR | wxOK);
+		return;
 	}
 
-	// Verify loading
-	if (ok) filename = _filename;
-	else LoadDefault();
-
 	// Set general data
 	loaded = true;
+	filename = _filename;
 
 	// Add comments and set vars
 	AddComment(_T("Script generated by Aegisub ") + GetAegisubLongVersionString());
@@ -152,11 +135,15 @@ void AssFile::Load (const wxString &_filename,wxString charset,bool addToRecent)
 	SetScriptInfo(_T("ScriptType"),_T("v4.00+"));
 
 	// Push the initial state of the file onto the undo stack
-	Commit("", commitId);
+	UndoStack.clear();
-	savedCommitId = commitId;
+	RedoStack.clear();
+	undoDescription.clear();
+	commitId = -1;
+	savedCommitId = 0;
+	Commit("");
 
 	// Add to recent
-	if (addToRecent && ok) AddToRecent(_filename);
+	if (addToRecent) AddToRecent(_filename);
 }
 
 void AssFile::Save(wxString _filename,bool setfilename,bool addToRecent,const wxString encoding) {
@@ -771,8 +758,8 @@ wxString AssFile::GetWildcardList(int mode) {
 int AssFile::Commit(wxString desc, int amendId) {
 	++commitId;
 	// Allow coalescing only if it's the last change and the file has not been
-	// saved since the last change and the undo stack isn't empty
+	// saved since the last change
-	if (commitId == amendId+1 && RedoStack.empty() && savedCommitId != commitId && !UndoStack.empty()) {
+	if (commitId == amendId+1 && RedoStack.empty() && savedCommitId != commitId) {
 		UndoStack.back() = *this;
 		return commitId;
 	}