Fix for issue 3723 - Tabbing on single-line character range should re…

…place characters with tab

src/editor/Editor.js

@@ -119,8 +119,7 @@ define(function (require, exports, module) {
         //    the proper indentation then indent it to the proper place. Otherwise,
         //    add another tab. In either case, move the insertion point to the 
         //    beginning of the text.
-        // 2. If the selection is after the first non-space character, and is not an 
-        //    insertion point, indent the entire line(s).
+        // 2. If the selection is multi-line, indent all the lines.
         // 3. If the selection is after the first non-space character, and is an 
         //    insertion point, insert a tab character or the appropriate number 
         //    of spaces to pad to the nearest tab boundary.
@@ -144,7 +143,7 @@ define(function (require, exports, module) {
                 insertTab = true;
                 to.ch = 0;
             }
-        } else if (instance.somethingSelected()) {
+        } else if (instance.somethingSelected() && from.line !== to.line) {
             CodeMirror.commands.indentMore(instance);
         } else {
             insertTab = true;