Mac: Fix Korean input on OSX 10.11

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 2083 matching lines @@
   DCHECK(!handlingKeyDown_);
 
   // Tells insertText: and doCommandBySelector: that we are handling a key
   // down event.
   handlingKeyDown_ = YES;
 
   // These variables might be set when handling the keyboard event.
   // Clear them here so that we can know whether they have changed afterwards.
   textToBeInserted_.clear();
   markedText_.clear();
+  markedTextSelectedRange_ = NSMakeRange(NSNotFound, 0);
   underlines_.clear();
   unmarkTextCalled_ = NO;
   hasEditCommands_ = NO;
   editCommands_.clear();
 
   // Before doing anything with a key down, check to see if plugin IME has been
   // cancelled, since the plugin host needs to be informed of that before
   // receiving the keydown.
   if ([theEvent type] == NSKeyDown)
     [self checkForPluginImeCancellation];
@@ skipping 63 matching lines @@
     widgetHost->ImeConfirmComposition(
         textToBeInserted_, gfx::Range::InvalidRange(), false);
     textInserted = YES;
   }
 
   // Updates or cancels the composition. If some text has been inserted, then
   // we don't need to cancel the composition explicitly.
   if (hasMarkedText_ && markedText_.length()) {
     // Sends the updated marked text to the renderer so it can update the
     // composition node in WebKit.
-    // When marked text is available, |selectedRange_| will be the range being
-    // selected inside the marked text.
+    // When marked text is available, |markedTextSelectedRange_| will be the
+    // range being selected inside the marked text.
     widgetHost->ImeSetComposition(markedText_, underlines_,
-                                  selectedRange_.location,
-                                  NSMaxRange(selectedRange_));
+                                  markedTextSelectedRange_.location,
+                                  NSMaxRange(markedTextSelectedRange_));
   } else if (oldHasMarkedText && !hasMarkedText_ && !textInserted) {
     if (unmarkTextCalled_) {
       widgetHost->ImeConfirmComposition(
           base::string16(), gfx::Range::InvalidRange(), false);
     } else {
       widgetHost->ImeCancelComposition();
     }
   }
 
   // If the key event was handled by the input method but it also generated some
@@ skipping 654 matching lines @@
                          actualRange:(NSRangePointer)actualRange {
   NSRect rect = [self firstViewRectForCharacterRange:theRange
                                          actualRange:actualRange];
 
   // Convert into screen coordinates for return.
   rect = [self convertRect:rect toView:nil];
   rect.origin = [[self window] convertBaseToScreen:rect.origin];
   return rect;
 }
 
+- (NSRange)selectedRange {
+  if (hasMarkedText_)
+    return NSMakeRange(NSMaxRange(markedRange_), 0);

[James Su, 2015/07/17 03:47:37]

I'm not sure if this logic is necessary. The developer document:
https://developer.apple.com/library/mac/documentation/Cocoa/Reference/NSTextI...
doesn't mention this behavior.

Can you remove this whole method and test the behavior?

[Andre, 2015/07/17 18:05:44]

Thanks James.
This is actually the main fix for the bug.
AppKit calls this then calls -attributedSubstringForProposedRange:actualRange:
based on the returned value.
It ends up asking for the wrong substring for working with the current
composition because selectedRange is
wrong.
The selection caret is placed after the marked text, so selectedRange should
point the end of the text,
but the selectedRange we get from blink does not include the marked text for
some reason.
For example, if we have 2 commited characters and 1 character marked text,
selectedRange should be (3, 0)
but we were returning (2,0).

[James Su, 2015/07/18 02:26:33]

Can you investigate the root cause of this issue? I'd prefer to fix the root
cause rather than workaround the issue here.

+
+  return selectedRange_;
+}
+
 - (NSRange)markedRange {
   // An input method calls this method to check if an application really has
   // a text being composed when hasMarkedText call returns true.
   // Returns the range saved in the setMarkedText method so the input method
   // calls the setMarkedText method and we can update the composition node
   // there. (When this method returns an empty range, the input method doesn't
   // call the setMarkedText method.)
   return hasMarkedText_ ? markedRange_ : NSMakeRange(NSNotFound, 0);
 }
 
@@ skipping 39 matching lines @@
 }
 
 - (void)unmarkText {
   // Delete the composition node of the renderer and finish an ongoing
   // composition.
   // It seems an input method calls the setMarkedText method and set an empty
   // text when it cancels an ongoing composition, i.e. I have never seen an
   // input method calls this method.
   hasMarkedText_ = NO;
   markedText_.clear();
+  markedTextSelectedRange_ = NSMakeRange(NSNotFound, 0);
   underlines_.clear();
 
   // If we are handling a key down event, then ConfirmComposition() will be
   // called in keyEvent: method.
   if (!handlingKeyDown_) {
     renderWidgetHostView_->render_widget_host_->ImeConfirmComposition(
         base::string16(), gfx::Range::InvalidRange(), false);
   } else {
     unmarkTextCalled_ = YES;
   }
 }
 
 - (void)setMarkedText:(id)string selectedRange:(NSRange)newSelRange
                               replacementRange:(NSRange)replacementRange {
   // An input method updates the composition string.
   // We send the given text and range to the renderer so it can update the
   // composition node of WebKit.
   // TODO(suzhe): It's hard for us to support replacementRange without accessing
   // the full web content.
   BOOL isAttributedString = [string isKindOfClass:[NSAttributedString class]];
   NSString* im_text = isAttributedString ? [string string] : string;
   int length = [im_text length];
 
   // |markedRange_| will get set on a callback from ImeSetComposition().
-  selectedRange_ = newSelRange;
+  markedTextSelectedRange_ = newSelRange;
   markedText_ = base::SysNSStringToUTF16(im_text);
   hasMarkedText_ = (length > 0);
 
   underlines_.clear();
   if (isAttributedString) {
     ExtractUnderlines(string, &underlines_);
   } else {
     // Use a thin black underline by default.
     underlines_.push_back(blink::WebCompositionUnderline(
         0, length, SK_ColorBLACK, false, SK_ColorTRANSPARENT));
@@ skipping 344 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end