Fix selection bug on Safari

See comment in code for details. Fixes #90

Author: marijnh

lib/codemirror.js

@@ -1893,6 +1893,7 @@ var CodeMirror = (function() {
 
   var gecko = /gecko\/\d{7}/i.test(navigator.userAgent);
   var ie = /MSIE \d/.test(navigator.userAgent);
+  var safari = /Apple Computer/.test(navigator.vendor);
 
   var lineSep = "\n";
   // Feature-detect whether newlines in textareas are converted to \r\n
@@ -1993,10 +1994,26 @@ var CodeMirror = (function() {
       try {return {start: te.selectionStart, end: te.selectionEnd};}
       catch(e) {return null;}
     };
-    var setSelRange = function(te, start, end) {
-      try {te.setSelectionRange(start, end);}
-      catch(e) {} // Fails on Firefox when textarea isn't part of the document
-    };
+    if (safari)
+      // On Safari, selection set with setSelectionRange are in a sort
+      // of limbo wrt their anchor. If you press shift-left in them,
+      // the anchor is put at the end, and the selection expanded to
+      // the left. If you press shift-right, the anchor ends up at the
+      // front. This is not what CodeMirror wants, so it does a
+      // spurious modify() call to get out of limbo.
+      var setSelRange = function(te, start, end) {
+        if (start == end)
+          te.setSelectionRange(start, end);
+        else {
+          te.setSelectionRange(start, end - 1);
+          window.getSelection().modify("expand", "forward", "character");
+        }
+      };
+    else
+      var setSelRange = function(te, start, end) {
+        try {te.setSelectionRange(start, end);}
+        catch(e) {} // Fails on Firefox when textarea isn't part of the document
+      };
   }
   // IE model. Don't ask.
   else {