Ignore shift status in API-driven selection changes

Holding shift and then moving the cursor through the API would cause a
'selection extension' to happen, instead of simply moving the
selection to its new state. Most visible when bindin shift-key combos
to some editing function.

lib/codemirror.js

@@ -218,7 +218,7 @@ var CodeMirror = (function() {
       e.stop();
       if (ld && +new Date - ld < 400) return selectLine(start.line);
 
-      setCursor(start.line, start.ch, false);
+      setCursor(start.line, start.ch, true);
       // And then we have to see if it's a drag event, in which case
       // the dragged-over text must be selected.
       function end() {
@@ -231,7 +231,7 @@ var CodeMirror = (function() {
         if (cur && !posEq(cur, last)) {
           if (!focused) onFocus();
           last = cur;
-          setSelection(start, cur);
+          setSelectionUser(start, cur);
           updateInput = false;
           var visible = visibleLines();
           if (cur.line >= visible.to || cur.line < visible.from)
@@ -247,7 +247,7 @@ var CodeMirror = (function() {
       var up = connect(document, "mouseup", operation(function(e) {
         clearTimeout(going);
         var cur = posFromMouse(e);
-        if (cur) setSelection(start, cur);
+        if (cur) setSelectionUser(start, cur);
         e.stop();
         end();
       }), true);
@@ -820,17 +820,20 @@ var CodeMirror = (function() {
       else cursor.style.display = "none";
     }
 
+    function setSelectionUser(from, to) {
+      var sh = shiftSelecting && clipPos(shiftSelecting);
+      if (sh) {
+        if (posLess(sh, from)) from = sh;
+        else if (posLess(to, sh)) to = sh;
+      }
+      setSelection(from, to);
+    }
     // Update the selection. Last two args are only used by
     // updateLines, since they have to be expressed in the line
     // numbers before the update.
     function setSelection(from, to, oldFrom, oldTo) {
       if (posEq(sel.from, from) && posEq(sel.to, to)) return;
-      var sh = shiftSelecting && clipPos(shiftSelecting);
       if (posLess(to, from)) {var tmp = to; to = from; from = tmp;}
-      if (sh) {
-        if (posLess(sh, from)) from = sh;
-        else if (posLess(to, sh)) to = sh;
-      }
 
       var startEq = posEq(sel.to, to), endEq = posEq(sel.from, from);
       if (posEq(from, to)) sel.inverted = false;
@@ -865,9 +868,9 @@ var CodeMirror = (function() {
       sel.from = from; sel.to = to;
       selectionChanged = true;
     }
-    function setCursor(line, ch) {
+    function setCursor(line, ch, user) {
       var pos = clipPos({line: line, ch: ch || 0});
-      setSelection(pos, pos);
+      (user ? setSelectionUser : setSelection)(pos, pos);
     }
 
     function clipLine(n) {return Math.max(0, Math.min(n, lines.length-1));}
@@ -882,10 +885,10 @@ var CodeMirror = (function() {
 
     function scrollPage(down) {
       var linesPerPage = Math.floor(wrapper.clientHeight / lineHeight()), head = sel.inverted ? sel.from : sel.to;
-      setCursor(head.line + (Math.max(linesPerPage - 1, 1) * (down ? 1 : -1)), head.ch);
+      setCursor(head.line + (Math.max(linesPerPage - 1, 1) * (down ? 1 : -1)), head.ch, true);
     }
     function scrollEnd(top) {
-      setCursor(top ? 0 : lines.length - 1);
+      setCursor(top ? 0 : lines.length - 1, true);
     }
     function selectAll() {
       var endLine = lines.length - 1;
@@ -896,10 +899,10 @@ var CodeMirror = (function() {
       var start = pos.ch, end = pos.ch;
       while (start > 0 && /\w/.test(line.charAt(start - 1))) --start;
       while (end < line.length && /\w/.test(line.charAt(end))) ++end;
-      setSelection({line: pos.line, ch: start}, {line: pos.line, ch: end});
+      setSelectionUser({line: pos.line, ch: start}, {line: pos.line, ch: end});
     }
     function selectLine(line) {
-      setSelection({line: line, ch: 0}, {line: line, ch: lines[line].text.length});
+      setSelectionUser({line: line, ch: 0}, {line: line, ch: lines[line].text.length});
     }
     function handleEnter() {
       replaceSelection("\n", "end");