From: Thomas Faber <thfabba@gmx.de>
Subject: riched20: do not return incorrect values from ME_CharFromPoint[Cursor]
Message-Id: <4EA32B76.3000507@gmx.de>
Date: Sat, 22 Oct 2011 22:45:42 +0200

This is the correct fix for the problem I previously described [1].
ME_CharFromPoint is called with cx < 0 if the richedit control has zero or
otherwise very small width.
Windows's version of GetTextExtentExPointW, which is called in that function,
returns a value of 1 in this case (Wine's does not, which would appear to be
a bug), leading to the "i<len" assertion failure if there is no text in the
control.
The patch fixes riched20 to correctly handle either behavior by
adding a fast path for cx <= 0 (the function obviously needs to return 0 in
the cx == 0 case too, so it can skip the calculation).

[1] http://www.winehq.org/pipermail/wine-patches/2011-October/107895.html

From dbb439c98837084d8a596793b1edd5f83f4826c1 Mon Sep 17 00:00:00 2001
From: Thomas Faber <thfabba@gmx.de>
Date: Sat, 22 Oct 2011 21:41:28 +0200
Subject: riched20: do not return incorrect values from ME_CharFromPoint[Cursor]

---
 dlls/riched20/run.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/dlls/riched20/run.c b/dlls/riched20/run.c
index 4a9ae7a..8a1f91f 100644
--- a/dlls/riched20/run.c
+++ b/dlls/riched20/run.c
@@ -434,7 +434,7 @@ int ME_CharFromPoint(ME_Context *c, int cx, ME_Run *run)
   int fit = 0;
   HGDIOBJ hOldFont;
   SIZE sz;
-  if (!run->strText->nLen)
+  if (!run->strText->nLen || cx <= 0)
     return 0;
 
   if (run->nFlags & MERF_TAB ||
@@ -492,7 +492,7 @@ int ME_CharFromPointCursor(ME_TextEditor *editor, int cx, ME_Run *run)
   ME_Context c;
   HGDIOBJ hOldFont;
   SIZE sz, sz2, sz3;
-  if (!run->strText->nLen)
+  if (!run->strText->nLen || cx <= 0)
     return 0;
 
   if (run->nFlags & (MERF_TAB | MERF_ENDCELL))
-- 
1.7.1.GIT