editor, allow temporarily column selection even if option eoScrollPastEol not enabled

src/ce_dubproject.pas

@@ -203,7 +203,7 @@ begin
     //
     FreeAndNil(fJSON);
     parser := TJSONParser.Create(loader, true);
-    //TODO-cDUB: uses parser.options to allow trailing comma (from FPC 3.02)
+    //TODO-cgonnawork: from FPC 3.02, uses parser.options to allow trailing comma in DUB descriptions
     // http://bugs.freepascal.org/view.php?id=29357
     try
       try

src/ce_main.pas

@@ -1025,7 +1025,7 @@ begin
   try
     DockMaster.SaveLayoutToConfig(xcfg);
     xcfg.WriteToDisk;
-    // TODO: remove this when AnchorDocking wont save anymore invalid layout
+    // TODO-cdocking: remove this when AnchorDocking wont save anymore invalid layout
     with TMemoryStream.Create do try
       LoadFromFile(getCoeditDocPath + 'docking.xml.tmp');
       if Size < 10000 then
@@ -1148,7 +1148,7 @@ begin
       LoadLastDocsAndProj;
 
     // http://bugs.freepascal.org/view.php?id=29475
-    // TODO-cbugfix: activate this when Laz 1.6 released.
+    // TODO-cgonnawork: activate this when Laz 1.6 released.
     // DockMaster.ResetSplitter;
 
     fFirstShown := true;
@@ -2098,7 +2098,7 @@ begin
     DockMaster.SaveLayoutToConfig(xcfg);
     xcfg.WriteToDisk;
     // prevent any invalid layout to be saved (AnchorDocking bug)
-    // TODO: remove this when AnchorDocking wont save anymore invalid layout
+    // TODO-cdocking: remove this when AnchorDocking wont save anymore invalid layout
     with TMemoryStream.Create do try
       LoadFromFile(aFilename + '.tmp');
       if Size < 10000 then
@@ -2176,7 +2176,7 @@ begin
     widg.Parent.Parent.isNil and widg.isDockable then
   begin
     TForm(widg.Parent).FormStyle := fstyle[onTop];
-    //TODO-bugfix: floating widg on top from true to false, widg remains on top
+    //TODO-cbugfix: floating widg on top from true to false, widg remains on top
     if TForm(widg.Parent).Visible then if not onTop then
       TForm(widg.Parent).SendToBack;
   end;

src/ce_synmemo.pas

@@ -130,6 +130,7 @@ type
     fMatchIdentOpts: TSynSearchOptions;
     fMatchOpts: TIdentifierMatchOptions;
     fCallTipStrings: TStringList;
+    fOverrideColMode: boolean;
     procedure setMatchOpts(value: TIdentifierMatchOptions);
     function getMouseFileBytePos: Integer;
     procedure changeNotify(Sender: TObject);
@@ -309,7 +310,7 @@ begin
   fFontSize := fMemo.Font.Size;
   TCEEditorHintWindow.FontSize := fMemo.Font.Size;
   //
-  // TODO-cEditor Cache: >nested< folding persistence
+  // TODO-cimprovment: handle nested folding in TCESynMemoCache
   // cf. other ways: http://forum.lazarus.freepascal.org/index.php?topic=26748.msg164722#msg164722
   prev := fMemo.Lines.Count-1;
   for i := fMemo.Lines.Count-1 downto 0 do
@@ -766,6 +767,11 @@ begin
       showCallTips;
     end;
   end;
+  if fOverrideColMode and not SelAvail then
+  begin
+    fOverrideColMode := false;
+    Options := Options - [eoScrollPastEol];
+  end;
 end;
 {$ENDREGIOn}
 
@@ -1243,6 +1249,12 @@ begin
   fCanShowHint := false;
   hideCallTips;
   hideDDocs;
+  if (emAltSetsColumnMode in MouseOptions) and not (eoScrollPastEol in Options)
+    and (ssLeft in shift) and (ssAlt in Shift) then
+  begin
+    fOverrideColMode := true;
+    Options := Options + [eoScrollPastEol];
+  end;
 end;
 
 procedure TCESynMemo.MouseUp(Button: TMouseButton; Shift: TShiftState; X, Y:Integer);
@@ -1251,11 +1263,15 @@ begin
   case Button of
     mbMiddle: if (Shift = [ssCtrl]) then
       Font.Size := fDefaultFontSize;
-    // linux, kde: mbExtra are never called
     mbExtra1: fPositions.back;
     mbExtra2: fPositions.next;
     mbLeft:   fPositions.store;
   end;
+  if fOverrideColMode and not SelAvail then
+  begin
+    fOverrideColMode := false;
+    Options := Options - [eoScrollPastEol];
+  end;
 end;
 
 function TCESynMemo.DoMouseWheel(Shift: TShiftState; WheelDelta: Integer; MousePos: TPoint): Boolean;