[Bug 2677890]: Fix odd text widget update problem that had scrollbars being

unable to cover the whole widget. Fix is to reify the range to update sooner.

3 files changed, 40 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 91a8270..d64f0a8 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2010-01-07  Donal K. Fellows  <dkf@users.sf.net>
+
+	* generic/tkTextDisp.c (AsyncUpdateLineMetrics): [Bug 2677890]: Fix
+	odd text widget update problem that had scrollbars being unable to
+	cover the whole widget. Fix is to reify the range to update sooner.
+
 2010-01-06  Donal K. Fellows  <dkf@users.sf.net>
 
 	* library/tk.tcl:		Centralize the definition of keys that
diff --git a/generic/tkTextDisp.c b/generic/tkTextDisp.c
index be9dd3b..9dc4316 100644
--- a/generic/tkTextDisp.c
+++ b/generic/tkTextDisp.c
@@ -12,7 +12,7 @@
  * See the file "license.terms" for information on usage and redistribution of
  * this file, and for a DISCLAIMER OF ALL WARRANTIES.
  *
- * RCS: @(#) $Id: tkTextDisp.c,v 1.76 2010/01/02 22:52:38 dkf Exp $
+ * RCS: @(#) $Id: tkTextDisp.c,v 1.77 2010/01/07 15:32:18 dkf Exp $
  */
 
 #include "tkInt.h"
@@ -2902,9 +2902,15 @@ AsyncUpdateLineMetrics(
 	return;
     }
 
+    /*
+     * Reify where we end or all hell breaks loose with the calculations when
+     * we try to update. [Bug 2677890]
+     */
+
     lineNum = dInfoPtr->currentMetricUpdateLine;
-    if (lineNum == -1) {
-	dInfoPtr->lastMetricUpdateLine = 0;
+    if (dInfoPtr->lastMetricUpdateLine == -1) {
+	dInfoPtr->lastMetricUpdateLine =
+		TkBTreeNumLines(textPtr->sharedTextPtr->tree, textPtr);
     }
 
     /*
diff --git a/tests/textDisp.test b/tests/textDisp.test
index 6d3212c..1d72ca5 100644
--- a/tests/textDisp.test
+++ b/tests/textDisp.test
@@ -6,7 +6,7 @@
 # Copyright (c) 1998-1999 by Scriptics Corporation.
 # All rights reserved.
 #
-# RCS: @(#) $Id: textDisp.test,v 1.43 2008/10/08 20:15:26 dgp Exp $
+# RCS: @(#) $Id: textDisp.test,v 1.44 2010/01/07 15:32:18 dkf Exp $
 
 package require tcltest 2.1
 eval tcltest::configure $argv
@@ -3846,6 +3846,30 @@ test textDisp-33.5 {bold or italic fonts} win {
 } {italic font measurement ok}
 destroy .tt
 
+test textDisp-34.1 {Text widgets multi-scrolling problem: Bug 2677890} -setup {
+    pack [text .t1 -width 10 -yscrollcommand {.sy set}] \
+	[ttk::scrollbar .sy -orient vertical -command {.t1 yview}] \
+	-side left -fill both
+    bindtags .sy {}; # No clicky!
+    set txt ""
+    for {set i 0} {$i < 99} {incr i} {
+	lappend txt "$i" [list pc $i] "\n" ""
+    }
+    set result {}
+} -body {
+    .t1 insert end {*}$txt
+    update
+    lappend result [.sy get]
+    .t1 replace 6.0 6.0+1c "*"
+    lappend result [.sy get]
+    after 0 {lappend result [.sy get]}
+    after 1000 {lappend result [.sy get]}
+    vwait result;vwait result
+    return $result
+} -cleanup {
+    destroy .t1 .sy
+} -result {{0.0 1.0} {0.0 1.0} {0.0 1.0} {0.0 0.24}}
+
 deleteWindows
 option clear