Be more careful about registering keys as movement keys

Closes #155

lib/codemirror.js

@@ -350,14 +350,16 @@ var CodeMirror = (function() {
       // its start when it is inverted and a movement key is pressed
       // (and later restore it again), shouldn't be used for
       // non-movement keys.
-      curKeyId = (mod ? "c" : "") + code;
-      if (sel.inverted && movementKeys.hasOwnProperty(curKeyId)) {
+      curKeyId = (mod ? "c" : "") + (e.altKey ? "a" : "") + code;
+      if (sel.inverted && movementKeys[curKeyId] === true) {
         var range = selRange(input);
         if (range) {
           reducedSelection = {anchor: range.start};
           setSelRange(input, range.start, range.start);
         }
       }
+      // Don't save the key as a movementkey unless it had a modifier
+      if (!mod && !e.altKey) curKeyId = null;
       fastPoll(curKeyId);
     }
     function onKeyUp(e) {
@@ -569,7 +571,10 @@ var CodeMirror = (function() {
       function p() {
         startOperation();
         var changed = readInput();
-        if (changed == "moved" && keyId) movementKeys[keyId] = true;
+        if (changed && keyId) {
+          if (changed == "moved" && movementKeys[keyId] == null) movementKeys[keyId] = true;
+          if (changed == "changed") movementKeys[keyId] = false;
+        }
         if (!changed && !missed) {missed = true; poll.set(80, p);}
         else {pollingFast = false; slowPoll();}
         endOperation();