Don't do overwrite when pasting

lib/codemirror.js

@@ -75,7 +75,7 @@ window.CodeMirror = (function() {
     // Selection-related flags. shiftSelecting obviously tracks
     // whether the user is holding shift.
     var shiftSelecting, lastClick, lastDoubleClick, lastScrollTop = 0, draggingText,
-        overwrite = false, suppressEdits = false;
+        overwrite = false, suppressEdits = false, pasteIncoming = false;
     // Variables used by startOperation/endOperation to track what
     // happened during the operation.
     var updateInput, userSelChange, changes, textChanged, selectionChanged,
@@ -128,7 +128,7 @@ window.CodeMirror = (function() {
       connect(scroller, "drop", operation(onDrop));
     }
     connect(scroller, "paste", function(){focusInput(); fastPoll();});
-    connect(input, "paste", fastPoll);
+    connect(input, "paste", function(){pasteIncoming = true; fastPoll();});
     connect(input, "cut", operation(function(){
       if (!options.readOnly) replaceSelection("");
     }));
@@ -955,12 +955,13 @@ window.CodeMirror = (function() {
       while (same < l && prevInput[same] == text[same]) ++same;
       if (same < prevInput.length)
         sel.from = {line: sel.from.line, ch: sel.from.ch - (prevInput.length - same)};
-      else if (overwrite && posEq(sel.from, sel.to))
+      else if (overwrite && posEq(sel.from, sel.to) && !pasteIncoming)
         sel.to = {line: sel.to.line, ch: Math.min(getLine(sel.to.line).text.length, sel.to.ch + (text.length - same))};
       replaceSelection(text.slice(same), "end");
       if (text.length > 1000) { input.value = prevInput = ""; }
       else prevInput = text;
       if (!nestedOperation) endOperation();
+      pasteIncoming = false;
       return true;
     }
     function resetInput(user) {