diff --git a/aegisub/src/ass_file.cpp b/aegisub/src/ass_file.cpp
index d9516ac87..7086ade0f 100644
--- a/aegisub/src/ass_file.cpp
+++ b/aegisub/src/ass_file.cpp
@@ -165,7 +165,7 @@ void AssFile::Load(const wxString &_filename,wxString charset,bool addToRecent)
 	undoDescription.clear();
 	commitId = -1;
 	savedCommitId = 0;
-	Commit("");
+	Commit("", COMMIT_NEW);
 
 	// Add to recent
 	if (addToRecent) AddToRecent(filename);
@@ -468,7 +468,7 @@ void AssFile::LoadDefault(bool defline) {
 		AddLine(def.GetEntryData(),_T("[Events]"),version);
 	}
 
-	Commit("");
+	Commit("", COMMIT_NEW);
 	savedCommitId = commitId;
 	loaded = true;
 	StandardPaths::SetPathValue("?script", "");
@@ -760,14 +760,12 @@ wxString AssFile::GetWildcardList(int mode) {
 	else return "";
 }
 
-int AssFile::Commit(wxString desc, CommitType type, int amendId) {
-	assert(type != COMMIT_UNDO);
-
+int AssFile::Commit(wxString desc, int type, int amendId) {
 	++commitId;
 	// Allow coalescing only if it's the last change and the file has not been
 	// saved since the last change
 	if (commitId == amendId+1 && RedoStack.empty() && savedCommitId != commitId) {
-		UndoStack.back() = *this;
+			UndoStack.back() = *this;
 		AnnounceCommit(type);
 		return commitId;
 	}
@@ -801,7 +799,7 @@ void AssFile::Undo() {
 	UndoStack.pop_back();
 	*this = UndoStack.back();
 
-	AnnounceCommit(COMMIT_UNDO);
+	AnnounceCommit(COMMIT_NEW);
 }
 
 void AssFile::Redo() {
@@ -811,7 +809,7 @@ void AssFile::Redo() {
 	UndoStack.push_back(*this);
 	RedoStack.pop_back();
 
-	AnnounceCommit(COMMIT_UNDO);
+	AnnounceCommit(COMMIT_NEW);
 }
 
 wxString AssFile::GetUndoDescription() const {
diff --git a/aegisub/src/ass_file.h b/aegisub/src/ass_file.h
index 5b780b8fe..dc9e9f8f2 100644
--- a/aegisub/src/ass_file.h
+++ b/aegisub/src/ass_file.h
@@ -164,16 +164,32 @@ public:
 
 	/// Type of changes made in a commit
 	enum CommitType {
-		/// Entire file has been swapped for a different version of the same file
-		COMMIT_UNDO,
 		/// Potentially the entire file has been changed; any saved information
-		/// should be discarded
-		COMMIT_FULL,
-		/// The contents of lines have changed, but the number or order of lines
-		/// has not
-		COMMIT_TEXT,
-		/// Only the start and end times of lines has changed
-		COMMIT_TIMES
+		/// should be discarded. Note that the active line and selected set
+		/// should not be touched in handlers for this, as they may not have
+		/// been updated yet
+		/// Note that it is intentional that this cannot be combined with
+		/// other commit types
+		COMMIT_NEW         = 0,
+		/// The order of lines in the file has changed
+		COMMIT_ORDER       = 0x1,
+		/// The script info section has changed in some way
+		COMMIT_SCRIPTINFO  = 0x2,
+		/// The styles have changed in some way
+		COMMIT_STYLES      = 0x4,
+		/// The attachments have changed in some way
+		COMMIT_ATTACHMENT  = 0x8,
+		/// Dialogue lines have been added or removed
+		/// Note that if the active dialogue line was removed, the active line
+		/// should be updated BEFORE committing
+		COMMIT_DIAG_ADDREM = 0x10,
+		/// The metadata fields of existing dialogue lines have changed
+		COMMIT_DIAG_META   = 0x20,
+		/// The start and/or end times of existing dialogue lines have changed
+		COMMIT_DIAG_TIME   = 0x40,
+		/// The text of existing dialogue lines have changed
+		COMMIT_DIAG_TEXT   = 0x80,
+		COMMIT_DIAG_FULL   = COMMIT_DIAG_META | COMMIT_DIAG_TIME | COMMIT_DIAG_TEXT,
 	};
 
 	DEFINE_SIGNAL_ADDERS(AnnounceCommit, AddCommitListener)
@@ -185,7 +201,7 @@ public:
 	/// @param type     Type of changes made to the file in this commit
 	/// @param commitId Commit to amend rather than pushing a new commit
 	/// @return Unique identifier for the new undo group
-	int Commit(wxString desc, CommitType type = COMMIT_FULL, int commitId = -1);
+	int Commit(wxString desc, int type, int commitId = -1);
 	/// @brief Undo the last set of changes to the file
 	void Undo();
 	/// @brief Redo the last undone changes
diff --git a/aegisub/src/audio_timing_dialogue.cpp b/aegisub/src/audio_timing_dialogue.cpp
index bf514cefc..f8515fc73 100644
--- a/aegisub/src/audio_timing_dialogue.cpp
+++ b/aegisub/src/audio_timing_dialogue.cpp
@@ -319,9 +319,10 @@ void AudioTimingControllerDialogue::OnSelectedSetChanged(const Selection &lines_
 }
 
 void AudioTimingControllerDialogue::OnFileChanged(int type) {
-	if (type == AssFile::COMMIT_UNDO || type == AssFile::COMMIT_FULL) return;
-
-	Revert();
+	if (type & AssFile::COMMIT_DIAG_TIME)
+	{
+		Revert();
+	}
 }
 
 
@@ -387,11 +388,11 @@ void AudioTimingControllerDialogue::Commit()
 		commit_slot.Block();
 		if (user_triggered)
 		{
-			ass->Commit(_("timing"), AssFile::COMMIT_TIMES);
+			ass->Commit(_("timing"), AssFile::COMMIT_DIAG_TIME);
 			commit_id = -1; // never coalesce with a manually triggered commit
 		}
 		else
-			commit_id = ass->Commit(_("timing"), AssFile::COMMIT_TIMES, commit_id);
+			commit_id = ass->Commit(_("timing"), AssFile::COMMIT_DIAG_TIME, commit_id);
 
 		commit_slot.Unblock();
 		timing_modified = false;
diff --git a/aegisub/src/base_grid.cpp b/aegisub/src/base_grid.cpp
index 5305dd453..45eb2382f 100644
--- a/aegisub/src/base_grid.cpp
+++ b/aegisub/src/base_grid.cpp
@@ -898,6 +898,11 @@ void BaseGrid::SetColumnWidths() {
 	int total = 0;
 	for (int i=0;i<10;i++) total += colWidth[i];
 	colWidth[10] = w-total;
+
+	time_cols_x = labelLen + layerLen;
+	time_cols_w = startLen + endLen;
+	text_col_x = total;
+	text_col_w = colWidth[10];
 }
 
 /// @brief Get dialogue by index
diff --git a/aegisub/src/base_grid.h b/aegisub/src/base_grid.h
index fdabc824f..c4e978db6 100644
--- a/aegisub/src/base_grid.h
+++ b/aegisub/src/base_grid.h
@@ -108,6 +108,11 @@ protected:
 	int colWidth[16];      ///< Width in pixels of each column
 	agi::Context *context; ///< Current project context
 
+	int time_cols_x; ///< Left edge of the times columns
+	int time_cols_w; ///< Width of the two times columns
+	int text_col_x; ///< Left edge of the text column
+	int text_col_w; ///< Width of the text column
+
 	static const int columns = 10; ///< Total number of columns
 	bool showCol[columns]; ///< Column visibility mask
 
diff --git a/aegisub/src/command/edit.cpp b/aegisub/src/command/edit.cpp
index ad2053211..22017469b 100644
--- a/aegisub/src/command/edit.cpp
+++ b/aegisub/src/command/edit.cpp
@@ -181,7 +181,7 @@ static void combine_lines(agi::Context *c, void (*combiner)(AssDialogue *, AssDi
 	sel.insert(first);
 	c->selectionController->SetActiveLine(first);
 	c->selectionController->SetSelectedSet(sel);
-	c->ass->Commit(message);
+	c->ass->Commit(message, AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
 }
 
 static void combine_karaoke(AssDialogue *first, AssDialogue *second) {
@@ -311,7 +311,7 @@ struct edit_line_split_by_karaoke : public validate_sel_nonempty {
 			didSplit |= c->subsGrid->SplitLineByKaraoke(sels[i]);
 		}
 		if (didSplit) {
-			c->ass->Commit(_("splitting"));
+			c->ass->Commit(_("splitting"), AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
 		}
 		c->subsGrid->EndBatch();
 	}
@@ -338,7 +338,7 @@ struct edit_line_swap : public Command {
 
 			using std::swap;
 			swap(*a, *b);
-			c->ass->Commit(_("swap lines"));
+			c->ass->Commit(_("swap lines"), AssFile::COMMIT_ORDER);
 		}
 	}
 };
diff --git a/aegisub/src/command/grid.cpp b/aegisub/src/command/grid.cpp
index 62613cfd3..c3d41f48c 100644
--- a/aegisub/src/command/grid.cpp
+++ b/aegisub/src/command/grid.cpp
@@ -190,10 +190,7 @@ struct grid_swap_up : public Command {
 	void operator()(agi::Context *c) {
 		if (AssDialogue *line = c->selectionController->GetActiveLine()) {
 			if (move_one(c->ass->Line.rbegin(), c->ass->Line.rend(), line))
-				/// @todo Maybe add COMMIT_ORDER, as the grid is the only thing
-				///       that needs to care about this
-				///       Probably not worth it
-				c->ass->Commit(_("swap lines"), AssFile::COMMIT_FULL);
+				c->ass->Commit(_("swap lines"), AssFile::COMMIT_ORDER);
 		}
 	}
 };
@@ -213,7 +210,7 @@ struct grid_swap_down : public Command {
 		void operator()(agi::Context *c) {
 			if (AssDialogue *line = c->selectionController->GetActiveLine()) {
 				if (move_one(c->ass->Line.begin(), c->ass->Line.end(), line))
-					c->ass->Commit(_("swap lines"), AssFile::COMMIT_FULL);
+					c->ass->Commit(_("swap lines"), AssFile::COMMIT_ORDER);
 			}
 	}
 };
diff --git a/aegisub/src/command/time.cpp b/aegisub/src/command/time.cpp
index 06472e34d..a0845c557 100644
--- a/aegisub/src/command/time.cpp
+++ b/aegisub/src/command/time.cpp
@@ -147,7 +147,7 @@ struct time_frame_current : public validate_video_loaded {
 		}
 
 		// Commit
-		c->ass->Commit(_("shift to frame"), AssFile::COMMIT_TIMES);
+		c->ass->Commit(_("shift to frame"), AssFile::COMMIT_DIAG_TIME);
 	}
 };
 
@@ -204,7 +204,7 @@ struct time_snap_frame : public validate_video_loaded {
 			}
 		}
 
-		c->ass->Commit(_("shift to frame"));
+		c->ass->Commit(_("shift to frame"), AssFile::COMMIT_DIAG_TIME);
 	}
 };
 
@@ -259,7 +259,7 @@ struct time_snap_scene : public validate_video_loaded {
 		}
 
 		// Commit
-		c->ass->Commit(_("snap to scene"), AssFile::COMMIT_TIMES);
+		c->ass->Commit(_("snap to scene"), AssFile::COMMIT_DIAG_TIME);
 	}
 };
 
@@ -271,7 +271,7 @@ struct time_add_lead_in : public Command {
 	void operator()(agi::Context *c) {
 		if (AssDialogue *line = c->selectionController->GetActiveLine()) {
 			line->Start.SetMS(line->Start.GetMS() - OPT_GET("Audio/Lead/IN")->GetInt());
-			c->ass->Commit(_("add lead in"), AssFile::COMMIT_TIMES);
+			c->ass->Commit(_("add lead in"), AssFile::COMMIT_DIAG_TIME);
 		}
 	}
 };
@@ -284,7 +284,7 @@ struct time_add_lead_out : public Command {
 	void operator()(agi::Context *c) {
 		if (AssDialogue *line = c->selectionController->GetActiveLine()) {
 			line->End.SetMS(line->End.GetMS() + OPT_GET("Audio/Lead/OUT")->GetInt());
-			c->ass->Commit(_("add lead out"), AssFile::COMMIT_TIMES);
+			c->ass->Commit(_("add lead out"), AssFile::COMMIT_DIAG_TIME);
 		}
 	}
 };
@@ -312,7 +312,7 @@ struct time_sort_end : public Command {
 
 	void operator()(agi::Context *c) {
 		c->ass->Sort(AssFile::CompEnd);
-		c->ass->Commit(_("sort"));
+		c->ass->Commit(_("sort"), AssFile::COMMIT_ORDER);
 	}
 };
 
@@ -326,7 +326,7 @@ struct time_sort_start : public Command {
 
 	void operator()(agi::Context *c) {
 		c->ass->Sort();
-		c->ass->Commit(_("sort"));
+		c->ass->Commit(_("sort"), AssFile::COMMIT_ORDER);
 	}
 };
 
@@ -340,7 +340,7 @@ struct time_sort_style : public Command {
 
 	void operator()(agi::Context *c) {
 		c->ass->Sort(AssFile::CompStyle);
-		c->ass->Commit(_("sort"));
+		c->ass->Commit(_("sort"), AssFile::COMMIT_ORDER);
 	}
 };
 
diff --git a/aegisub/src/dialog_attachments.cpp b/aegisub/src/dialog_attachments.cpp
index 41d1051f0..4252d3dcb 100644
--- a/aegisub/src/dialog_attachments.cpp
+++ b/aegisub/src/dialog_attachments.cpp
@@ -174,7 +174,7 @@ DialogAttachments::~DialogAttachments() {
 	}
 
 	if (removed_any) {
-		ass->Commit(_("remove empty attachments sections"));
+		ass->Commit(_("remove empty attachments sections"), AssFile::COMMIT_ATTACHMENT);
 	}
 }
 
@@ -223,7 +223,7 @@ void DialogAttachments::OnAttachFont(wxCommandEvent &event) {
 		ass->InsertAttachment(newAttach);
 	}
 
-	ass->Commit(_("attach font file"));
+	ass->Commit(_("attach font file"), AssFile::COMMIT_ATTACHMENT);
 
 	// Update
 	UpdateList();
@@ -261,7 +261,7 @@ void DialogAttachments::OnAttachGraphics(wxCommandEvent &event) {
 		ass->InsertAttachment(newAttach);
 	}
 
-	ass->Commit(_("attach graphics file"));
+	ass->Commit(_("attach graphics file"), AssFile::COMMIT_ATTACHMENT);
 
 	// Update
 	UpdateList();
@@ -316,7 +316,7 @@ void DialogAttachments::OnDelete(wxCommandEvent &event) {
 		i = listView->GetNextSelected(i);
 	}
 
-	ass->Commit(_("remove attachment"));
+	ass->Commit(_("remove attachment"), AssFile::COMMIT_ATTACHMENT);
 
 	// Update list
 	UpdateList();
diff --git a/aegisub/src/dialog_fonts_collector.cpp b/aegisub/src/dialog_fonts_collector.cpp
index af208b61d..849011636 100644
--- a/aegisub/src/dialog_fonts_collector.cpp
+++ b/aegisub/src/dialog_fonts_collector.cpp
@@ -514,7 +514,7 @@ void FontsCollectorThread::Collect() {
 			// Modify file if it was attaching
 			if (oper == 3 && someOk) {
 				wxMutexGuiEnter();
-				subs->Commit(_("font attachment"));
+				subs->Commit(_("font attachment"), AssFile::COMMIT_ATTACHMENT);
 				wxMutexGuiLeave();
 			}
 		}
diff --git a/aegisub/src/dialog_kara_timing_copy.cpp b/aegisub/src/dialog_kara_timing_copy.cpp
index 028151691..6c9b3d7ee 100644
--- a/aegisub/src/dialog_kara_timing_copy.cpp
+++ b/aegisub/src/dialog_kara_timing_copy.cpp
@@ -947,7 +947,7 @@ void DialogKanjiTimer::OnClose(wxCommandEvent &event) {
 		line->Text = p.second;
 	}
 	if (modified) {
-		subs->Commit(_("kanji timing"));
+		subs->Commit(_("kanji timing"), AssFile::COMMIT_DIAG_TEXT);
 		LinesToChange.clear();
 	}
 	Close();
diff --git a/aegisub/src/dialog_properties.cpp b/aegisub/src/dialog_properties.cpp
index 30f7300f1..819361a1e 100644
--- a/aegisub/src/dialog_properties.cpp
+++ b/aegisub/src/dialog_properties.cpp
@@ -185,7 +185,7 @@ void DialogProperties::OnOK(wxCommandEvent &event) {
 	count += SetInfoIfDifferent("Collisions",col[collision->GetSelection()]);
 	count += SetInfoIfDifferent("ScaledBorderAndShadow",ScaleBorder->GetValue()? "yes" : "no");
 
-	if (count) c->ass->Commit(_("property changes"));
+	if (count) c->ass->Commit(_("property changes"), AssFile::COMMIT_SCRIPTINFO);
 
 	EndModal(!!count);
 }
diff --git a/aegisub/src/dialog_resample.cpp b/aegisub/src/dialog_resample.cpp
index 8c7d23518..3a26c188c 100644
--- a/aegisub/src/dialog_resample.cpp
+++ b/aegisub/src/dialog_resample.cpp
@@ -322,7 +322,7 @@ void DialogResample::OnResample (wxCommandEvent &event) {
 	c->ass->SetScriptInfo(_T("PlayResY"),wxString::Format(_T("%i"),y2));
 
 	// Flag as modified
-	c->ass->Commit(_("resolution resampling"), AssFile::COMMIT_TEXT);
+	c->ass->Commit(_("resolution resampling"), AssFile::COMMIT_SCRIPTINFO | AssFile::COMMIT_DIAG_FULL);
 	EndModal(0);
 }
 
diff --git a/aegisub/src/dialog_search_replace.cpp b/aegisub/src/dialog_search_replace.cpp
index 7ef7a8e0b..9666c6e8d 100644
--- a/aegisub/src/dialog_search_replace.cpp
+++ b/aegisub/src/dialog_search_replace.cpp
@@ -442,7 +442,7 @@ void SearchReplaceEngine::ReplaceNext(bool DoReplace) {
 			}
 
 			// Commit
-			context->ass->Commit(_("replace"), AssFile::COMMIT_TEXT);
+			context->ass->Commit(_("replace"), AssFile::COMMIT_DIAG_TEXT);
 		}
 
 		else {
@@ -546,7 +546,7 @@ void SearchReplaceEngine::ReplaceAll() {
 
 	// Commit
 	if (count > 0) {
-		context->ass->Commit(_("replace"), AssFile::COMMIT_TEXT);
+		context->ass->Commit(_("replace"), AssFile::COMMIT_DIAG_TEXT);
 		wxMessageBox(wxString::Format(_("%i matches were replaced."),count));
 	}
 
diff --git a/aegisub/src/dialog_shift_times.cpp b/aegisub/src/dialog_shift_times.cpp
index 8707e2cec..14c269079 100644
--- a/aegisub/src/dialog_shift_times.cpp
+++ b/aegisub/src/dialog_shift_times.cpp
@@ -318,7 +318,7 @@ void DialogShiftTimes::OnOK(wxCommandEvent &event) {
 	OPT_SET("Tool/Shift Times/Direction")->SetBool(backward);
 
 	// End dialog
-	context->ass->Commit(_("shifting"), AssFile::COMMIT_TIMES);
+	context->ass->Commit(_("shifting"), AssFile::COMMIT_DIAG_TIME);
 	EndModal(0);
 }
 
diff --git a/aegisub/src/dialog_style_editor.cpp b/aegisub/src/dialog_style_editor.cpp
index d6fd39067..9309da8ed 100644
--- a/aegisub/src/dialog_style_editor.cpp
+++ b/aegisub/src/dialog_style_editor.cpp
@@ -470,6 +470,7 @@ void DialogStyleEditor::Apply (bool apply,bool close) {
 		}
 
 		// Style name change
+		bool did_rename = false;
 		if (work->name != newStyleName) {
 			if (!isNew && isLocal) {
 				// See if user wants to update style name through script
@@ -481,6 +482,7 @@ void DialogStyleEditor::Apply (bool apply,bool close) {
 
 				// Update
 				if (answer == wxYES) {
+					did_rename = true;
 					int n = c->subsGrid->GetRows();
 					wxArrayString strings;
 					strings.Add(work->name);
@@ -507,7 +509,7 @@ void DialogStyleEditor::Apply (bool apply,bool close) {
 		*style = *work;
 		style->UpdateData();
 		if (isLocal) {
-			c->ass->Commit(_("style change"), AssFile::COMMIT_TEXT);
+			c->ass->Commit(_("style change"), AssFile::COMMIT_STYLES | (did_rename ? AssFile::COMMIT_DIAG_FULL : 0));
 		}
 
 		// Exit
diff --git a/aegisub/src/dialog_style_manager.cpp b/aegisub/src/dialog_style_manager.cpp
index df5d4c586..1c52bab97 100644
--- a/aegisub/src/dialog_style_manager.cpp
+++ b/aegisub/src/dialog_style_manager.cpp
@@ -595,7 +595,7 @@ void DialogStyleManager::OnCopyToCurrent (wxCommandEvent &) {
 	for (list<wxString>::iterator name = copied.begin(); name != copied.end(); ++name) {
 		CurrentList->SetStringSelection(*name, true);
 	}
-	c->ass->Commit(_("style copy"));
+	c->ass->Commit(_("style copy"), AssFile::COMMIT_STYLES);
 	wxCommandEvent dummy;
 	OnCurrentChange(dummy);
 }
@@ -643,7 +643,7 @@ void DialogStyleManager::OnCurrentCopy (wxCommandEvent &) {
 	}
 	else delete temp;
 
-	c->ass->Commit(_("style copy"));
+	c->ass->Commit(_("style copy"), AssFile::COMMIT_STYLES);
 	UpdateMoveButtons();
 }
 
@@ -695,7 +695,7 @@ void DialogStyleManager::PasteToCurrent() {
 				c->ass->InsertStyle(s);
 				LoadCurrentStyles(c->ass);
 
-				c->ass->Commit(_("style paste"));
+				c->ass->Commit(_("style paste"), AssFile::COMMIT_STYLES);
 			}
 			else
 				wxMessageBox(_("Could not parse style"), _("Could not parse style"), wxOK | wxICON_EXCLAMATION , this);
@@ -840,7 +840,7 @@ void DialogStyleManager::OnCurrentDelete (wxCommandEvent &) {
 		CurrentCopy->Enable(false);
 		CurrentDelete->Enable(false);
 
-		c->ass->Commit(_("style delete"));
+		c->ass->Commit(_("style delete"), AssFile::COMMIT_STYLES);
 	}
 	UpdateMoveButtons();
 }
@@ -901,7 +901,7 @@ void DialogStyleManager::OnCurrentImport(wxCommandEvent &) {
 			// Update
 			if (modified) {
 				LoadCurrentStyles(c->ass);
-				c->ass->Commit(_("style import"));
+				c->ass->Commit(_("style import"), AssFile::COMMIT_STYLES);
 			}
 		}
 		catch (...) {
@@ -1095,7 +1095,7 @@ void DialogStyleManager::MoveStyles(bool storage, int type) {
 		}
 
 		// Flag as modified
-		c->ass->Commit(_("style move"));
+		c->ass->Commit(_("style move"), AssFile::COMMIT_STYLES);
 	}
 
 	// Update
diff --git a/aegisub/src/dialog_styling_assistant.cpp b/aegisub/src/dialog_styling_assistant.cpp
index 107b3c876..3bc5dd840 100644
--- a/aegisub/src/dialog_styling_assistant.cpp
+++ b/aegisub/src/dialog_styling_assistant.cpp
@@ -187,7 +187,7 @@ void DialogStyling::Commit(bool next) {
 	if (!c->ass->GetStyle(style_name->GetValue())) return;
 
 	active_line->Style = style_name->GetValue();
-	c->ass->Commit(_("styling assistant"), AssFile::COMMIT_TEXT);
+	c->ass->Commit(_("styling assistant"), AssFile::COMMIT_DIAG_META);
 
 	if (next) cmd::call("grid/line/next", c);
 }
diff --git a/aegisub/src/dialog_timing_processor.cpp b/aegisub/src/dialog_timing_processor.cpp
index 9f5de3142..e7c50026a 100644
--- a/aegisub/src/dialog_timing_processor.cpp
+++ b/aegisub/src/dialog_timing_processor.cpp
@@ -466,5 +466,5 @@ void DialogTimingProcessor::Process() {
 	}
 
 	// Update grid
-	c->ass->Commit(_("timing processor"), AssFile::COMMIT_TIMES);
+	c->ass->Commit(_("timing processor"), AssFile::COMMIT_DIAG_TIME);
 }
diff --git a/aegisub/src/dialog_translation.cpp b/aegisub/src/dialog_translation.cpp
index bf3c11d9f..f98c2186d 100644
--- a/aegisub/src/dialog_translation.cpp
+++ b/aegisub/src/dialog_translation.cpp
@@ -235,7 +235,7 @@ void DialogTranslation::UpdateDisplay() {
 void DialogTranslation::Commit(bool next) {
 	active_line->Blocks[cur_block]->text = translated_text->GetValue();
 	active_line->UpdateText();
-	c->ass->Commit(_("translation assistant"), AssFile::COMMIT_TEXT);
+	c->ass->Commit(_("translation assistant"), AssFile::COMMIT_DIAG_TEXT);
 
 	if (next) {
 		if (!NextBlock()) {
diff --git a/aegisub/src/frame_main.cpp b/aegisub/src/frame_main.cpp
index dde4f3855..22c4c6c45 100644
--- a/aegisub/src/frame_main.cpp
+++ b/aegisub/src/frame_main.cpp
@@ -449,7 +449,7 @@ void FrameMain::OnVideoOpen() {
 				// Always change script res
 				context->ass->SetScriptInfo("PlayResX", wxString::Format("%d", vidx));
 				context->ass->SetScriptInfo("PlayResY", wxString::Format("%d", vidy));
-				context->ass->Commit(_("Change script resolution"));
+				context->ass->Commit(_("Change script resolution"), AssFile::COMMIT_SCRIPTINFO);
 				break;
 			case 0:
 			default:
diff --git a/aegisub/src/subs_edit_box.cpp b/aegisub/src/subs_edit_box.cpp
index 713a9575c..279c0e982 100644
--- a/aegisub/src/subs_edit_box.cpp
+++ b/aegisub/src/subs_edit_box.cpp
@@ -338,11 +338,14 @@ SubsEditBox::~SubsEditBox() {
 
 void SubsEditBox::Update(int type) {
 	SetEvtHandlerEnabled(false);
-	if (type == AssFile::COMMIT_FULL || type == AssFile::COMMIT_UNDO) {
-		/// @todo maybe preserve selection over undo?
+
+	if (type == AssFile::COMMIT_NEW || type & AssFile::COMMIT_STYLES) {
 		StyleBox->Clear();
 		StyleBox->Append(c->ass->GetStyles());
+	}
 
+	if (type == AssFile::COMMIT_NEW) {
+		/// @todo maybe preserve selection over undo?
 		ActorBox->Freeze();
 		ActorBox->Clear();
 		int nrows = c->subsGrid->GetRows();
@@ -360,6 +363,7 @@ void SubsEditBox::Update(int type) {
 		SetEvtHandlerEnabled(true);
 		return;
 	}
+	if (!(type ^ AssFile::COMMIT_ORDER)) return;
 
 	SetControlsState(!!line);
 	if (!line) {
@@ -367,11 +371,17 @@ void SubsEditBox::Update(int type) {
 		return;
 	}
 
-	StartTime->SetTime(line->Start);
-	EndTime->SetTime(line->End);
-	Duration->SetTime(line->End-line->Start);
-	if (type != AssFile::COMMIT_TIMES) {
+	if (type & AssFile::COMMIT_DIAG_TIME) {
+		StartTime->SetTime(line->Start);
+		EndTime->SetTime(line->End);
+		Duration->SetTime(line->End-line->Start);
+	}
+
+	if (type & AssFile::COMMIT_DIAG_TEXT) {
 		TextEdit->SetTextTo(line->Text);
+	}
+
+	if (type & AssFile::COMMIT_DIAG_META) {
 		Layer->SetValue(line->Layer);
 		MarginL->ChangeValue(line->GetMarginString(0,false));
 		MarginR->ChangeValue(line->GetMarginString(1,false));
@@ -390,7 +400,7 @@ void SubsEditBox::OnActiveLineChanged(AssDialogue *new_line) {
 	SetEvtHandlerEnabled(false);
 	line = new_line;
 
-	Update(AssFile::COMMIT_TEXT);
+	Update(AssFile::COMMIT_DIAG_FULL);
 
 	/// @todo VideoContext should be doing this
 	if (c->videoController->IsLoaded()) {
@@ -465,22 +475,22 @@ void SubsEditBox::OnChange(wxStyledTextEvent &event) {
 }
 
 template<class T, class setter>
-void SubsEditBox::SetSelectedRows(setter set, T value, wxString desc, bool amend) {
+void SubsEditBox::SetSelectedRows(setter set, T value, wxString desc, int type, bool amend) {
 	using namespace std::tr1::placeholders;
 
 	for_each(sel.begin(), sel.end(), std::tr1::bind(set, _1, value));
 
-	commitId = c->ass->Commit(desc, AssFile::COMMIT_TEXT, (amend && desc == lastCommitType) ? commitId : -1);
+	commitId = c->ass->Commit(desc, type, (amend && desc == lastCommitType) ? commitId : -1);
 	lastCommitType = desc;
 }
 
 template<class T>
-void SubsEditBox::SetSelectedRows(T AssDialogue::*field, T value, wxString desc, bool amend) {
-	SetSelectedRows(field_setter<T>(field), value, desc, amend);
+void SubsEditBox::SetSelectedRows(T AssDialogue::*field, T value, wxString desc, int type, bool amend) {
+	SetSelectedRows(field_setter<T>(field), value, desc, type, amend);
 }
 
 void SubsEditBox::CommitText(wxString desc) {
-	SetSelectedRows(&AssDialogue::Text, TextEdit->GetText(), desc, true);
+	SetSelectedRows(&AssDialogue::Text, TextEdit->GetText(), desc, AssFile::COMMIT_DIAG_TEXT, true);
 }
 
 void SubsEditBox::CommitTimes(TimeField field) {
@@ -503,7 +513,7 @@ void SubsEditBox::CommitTimes(TimeField field) {
 		}
 	}
 
-	timeCommitId[field] = c->ass->Commit(_("modify times"), AssFile::COMMIT_TIMES, timeCommitId[field]);
+	timeCommitId[field] = c->ass->Commit(_("modify times"), AssFile::COMMIT_DIAG_TIME, timeCommitId[field]);
 }
 
 void SubsEditBox::OnSize(wxSizeEvent &evt) {
@@ -591,12 +601,12 @@ void SubsEditBox::SetControlsState(bool state) {
 
 
 void SubsEditBox::OnStyleChange(wxCommandEvent &) {
-	SetSelectedRows(&AssDialogue::Style, StyleBox->GetValue(), _("style change"));
+	SetSelectedRows(&AssDialogue::Style, StyleBox->GetValue(), _("style change"), AssFile::COMMIT_DIAG_META);
 }
 
 void SubsEditBox::OnActorChange(wxCommandEvent &) {
 	wxString actor = ActorBox->GetValue();
-	SetSelectedRows(&AssDialogue::Actor, actor, _("actor change"));
+	SetSelectedRows(&AssDialogue::Actor, actor, _("actor change"), AssFile::COMMIT_DIAG_META);
 
 	// Add actor to list
 	if (!actor.empty() && ActorBox->GetCount() && ActorBox->GetString(0).empty()) {
@@ -612,7 +622,7 @@ void SubsEditBox::OnLayerChange(wxSpinEvent &event) {
 }
 
 void SubsEditBox::OnLayerEnter(wxCommandEvent &) {
-	SetSelectedRows(&AssDialogue::Layer, Layer->GetValue(), _("layer change"));
+	SetSelectedRows(&AssDialogue::Layer, Layer->GetValue(), _("layer change"), AssFile::COMMIT_DIAG_META);
 }
 
 void SubsEditBox::OnStartTimeChange(wxCommandEvent &) {
@@ -630,12 +640,12 @@ void SubsEditBox::OnDurationChange(wxCommandEvent &) {
 	CommitTimes(TIME_DURATION);
 }
 void SubsEditBox::OnMarginLChange(wxCommandEvent &) {
-	SetSelectedRows(std::mem_fun(&AssDialogue::SetMarginString<0>), MarginL->GetValue(), _("MarginL change"));
+	SetSelectedRows(std::mem_fun(&AssDialogue::SetMarginString<0>), MarginL->GetValue(), _("MarginL change"), AssFile::COMMIT_DIAG_META);
 	if (line) MarginL->ChangeValue(line->GetMarginString(0, false));
 }
 
 void SubsEditBox::OnMarginRChange(wxCommandEvent &) {
-	SetSelectedRows(std::mem_fun(&AssDialogue::SetMarginString<1>), MarginR->GetValue(), _("MarginR change"));
+	SetSelectedRows(std::mem_fun(&AssDialogue::SetMarginString<1>), MarginR->GetValue(), _("MarginR change"), AssFile::COMMIT_DIAG_META);
 	if (line) MarginR->ChangeValue(line->GetMarginString(1, false));
 }
 
@@ -645,16 +655,16 @@ static void set_margin_v(AssDialogue* diag, wxString value) {
 }
 
 void SubsEditBox::OnMarginVChange(wxCommandEvent &) {
-	SetSelectedRows(set_margin_v, MarginV->GetValue(), _("MarginV change"));
+	SetSelectedRows(set_margin_v, MarginV->GetValue(), _("MarginV change"), AssFile::COMMIT_DIAG_META);
 	if (line) MarginV->ChangeValue(line->GetMarginString(2, false));
 }
 
 void SubsEditBox::OnEffectChange(wxCommandEvent &) {
-	SetSelectedRows(&AssDialogue::Effect, Effect->GetValue(), _("effect change"));
+	SetSelectedRows(&AssDialogue::Effect, Effect->GetValue(), _("effect change"), AssFile::COMMIT_DIAG_META);
 }
 
 void SubsEditBox::OnCommentChange(wxCommandEvent &event) {
-	SetSelectedRows(&AssDialogue::Comment, CommentBox->GetValue(), _("comment change"));
+	SetSelectedRows(&AssDialogue::Comment, CommentBox->GetValue(), _("comment change"), AssFile::COMMIT_DIAG_META);
 }
 
 int SubsEditBox::BlockAtPos(int pos) const {
diff --git a/aegisub/src/subs_edit_box.h b/aegisub/src/subs_edit_box.h
index ef074f203..46fac4ae9 100644
--- a/aegisub/src/subs_edit_box.h
+++ b/aegisub/src/subs_edit_box.h
@@ -171,17 +171,19 @@ class SubsEditBox : public wxPanel, protected SelectionListener<AssDialogue> {
 	/// @param set   Callable which does the setting
 	/// @param value Value to pass to set
 	/// @param desc  Undo description to use
+	/// @param type  Commit type to use
 	/// @param amend Coalesce sequences of commits of the same type
 	template<class T, class setter>
-	void SetSelectedRows(setter set, T value, wxString desc, bool amend = false);
+	void SetSelectedRows(setter set, T value, wxString desc, int type, bool amend = false);
 
 	/// @brief Set a field in each selected line to a specified value
 	/// @param field Field to set
 	/// @param value Value to set the field to
 	/// @param desc  Undo description to use
+	/// @param type  Commit type to use
 	/// @param amend Coalesce sequences of commits of the same type
 	template<class T>
-	void SetSelectedRows(T AssDialogue::*field, T value, wxString desc, bool amend = false);
+	void SetSelectedRows(T AssDialogue::*field, T value, wxString desc, int type, bool amend = false);
 
 	/// @brief Reload the current line from the file
 	/// @param type AssFile::CommitType
diff --git a/aegisub/src/subs_grid.cpp b/aegisub/src/subs_grid.cpp
index 57766686f..44826ecdb 100644
--- a/aegisub/src/subs_grid.cpp
+++ b/aegisub/src/subs_grid.cpp
@@ -87,19 +87,20 @@ SubtitlesGrid::~SubtitlesGrid() {
 }
 
 void SubtitlesGrid::OnSubtitlesCommit(int type) {
-	if (type == AssFile::COMMIT_FULL)
-		UpdateMaps();
-	else if (type == AssFile::COMMIT_UNDO)
+	if (type == AssFile::COMMIT_NEW)
 		UpdateMaps(true);
+	else if (type & AssFile::COMMIT_ORDER || type & AssFile::COMMIT_DIAG_ADDREM)
+		UpdateMaps(false);
 
-	if (type == AssFile::COMMIT_TIMES) {
-		// Refresh just the audio times columns
-		RefreshRect(wxRect(colWidth[0] + colWidth[1], 0, colWidth[2] + colWidth[3], GetClientSize().GetHeight()), false);
-	}
-	else {
+	if (type & AssFile::COMMIT_DIAG_META) {
 		SetColumnWidths();
 		Refresh(false);
+		return;
 	}
+	if (type & AssFile::COMMIT_DIAG_TIME)
+		RefreshRect(wxRect(time_cols_x, 0, time_cols_w, GetClientSize().GetHeight()), false);
+	if (type & AssFile::COMMIT_DIAG_TEXT)
+		RefreshRect(wxRect(text_col_x, 0, text_col_w, GetClientSize().GetHeight()), false);
 }
 
 void SubtitlesGrid::OnSubtitlesOpen() {
@@ -232,15 +233,14 @@ void SubtitlesGrid::RecombineLines() {
 		}
 	}
 
-	context->ass->Commit(_("combining"));
-
 	// Remove now non-existent lines from the selection
 	Selection lines;
 	transform(context->ass->Line.begin(), context->ass->Line.end(), inserter(lines, lines.begin()), cast<AssDialogue*>());
 	Selection newSel;
 	set_intersection(lines.begin(), lines.end(), selectedSet.begin(), selectedSet.end(), inserter(newSel, newSel.begin()));
 
-	if (newSel.empty()) return;
+	if (newSel.empty())
+		newSel.insert(*lines.begin());
 
 	// Restore selection
 	SetSelectedSet(newSel);
@@ -248,6 +248,8 @@ void SubtitlesGrid::RecombineLines() {
 		activeLine = *newSel.begin();
 	}
 	SetActiveLine(activeLine);
+
+	context->ass->Commit(_("combining"), AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
 }
 
 /// @brief Insert a line 
@@ -264,7 +266,7 @@ void SubtitlesGrid::InsertLine(AssDialogue *line,int n,bool after,bool update) {
 
 	// Update
 	if (update) {
-		context->ass->Commit(_("line insertion"));
+		context->ass->Commit(_("line insertion"), AssFile::COMMIT_DIAG_ADDREM);
 	}
 	else {
 		UpdateMaps();
@@ -380,7 +382,7 @@ void SubtitlesGrid::PasteLines(int n,bool pasteOver) {
 
 		// Update data post-insertion
 		if (inserted > 0) {
-			context->ass->Commit(_("paste"), pasteOver ? AssFile::COMMIT_TEXT : AssFile::COMMIT_FULL);
+			context->ass->Commit(_("paste"), pasteOver ? AssFile::COMMIT_DIAG_FULL : AssFile::COMMIT_DIAG_ADDREM);
 
 			// Set selection
 			if (!pasteOver) {
@@ -422,7 +424,7 @@ void SubtitlesGrid::DeleteLines(wxArrayInt target, bool flagModified) {
 	}
 
 	if (flagModified) {
-		context->ass->Commit(_("delete"));
+		context->ass->Commit(_("delete"), AssFile::COMMIT_DIAG_ADDREM);
 	}
 	else {
 		UpdateMaps();
@@ -462,7 +464,7 @@ void SubtitlesGrid::AdjoinLines(int n1,int n2,bool setStart) {
 		}
 	}
 
-	context->ass->Commit(_("adjoin"));
+	context->ass->Commit(_("adjoin"), AssFile::COMMIT_DIAG_TIME);
 }
 
 void SubtitlesGrid::DuplicateLines(int n1,int n2,bool nextFrame) {
@@ -526,7 +528,7 @@ void SubtitlesGrid::SplitLine(AssDialogue *n1,int pos,bool estimateTimes) {
 		n2->Start.SetMS(splitTime);
 	}
 
-	context->ass->Commit(_("split"));
+	context->ass->Commit(_("split"), AssFile::COMMIT_DIAG_ADDREM | AssFile::COMMIT_DIAG_FULL);
 }
 
 bool SubtitlesGrid::SplitLineByKaraoke(int lineNumber) {
@@ -587,7 +589,7 @@ void SubtitlesGrid::SetSubsToVideo(bool start) {
 	}
 
 	if (modified) {
-		context->ass->Commit(_("timing"), AssFile::COMMIT_TIMES);
+		context->ass->Commit(_("timing"), AssFile::COMMIT_DIAG_TIME);
 	}
 }
 
diff --git a/aegisub/src/video_display.cpp b/aegisub/src/video_display.cpp
index 5c568208e..0e61f8308 100644
--- a/aegisub/src/video_display.cpp
+++ b/aegisub/src/video_display.cpp
@@ -212,7 +212,7 @@ void VideoDisplay::OnVideoOpen() {
 }
 
 void VideoDisplay::OnCommit(int type) {
-	if (type == AssFile::COMMIT_FULL || type == AssFile::COMMIT_UNDO)
+	if (type == AssFile::COMMIT_NEW || type & AssFile::COMMIT_SCRIPTINFO)
 		con->videoController->GetScriptSize(scriptW, scriptH);
 	if (tool.get()) tool->Refresh();
 }
diff --git a/aegisub/src/visual_tool.cpp b/aegisub/src/visual_tool.cpp
index 83d122e17..c7b27af4e 100644
--- a/aegisub/src/visual_tool.cpp
+++ b/aegisub/src/visual_tool.cpp
@@ -247,7 +247,7 @@ void VisualTool<FeatureType>::Commit(wxString message) {
 	if (message.empty()) {
 		message = _("visual typesetting");
 	}
-	commitId = c->ass->Commit(message, AssFile::COMMIT_TEXT, commitId);
+	commitId = c->ass->Commit(message, AssFile::COMMIT_DIAG_TEXT, commitId);
 	externalChange = true;
 }