Fixed bug [1669632fff] case (vii) - <<Undo>> shall not remove separators

2 files changed, 25 insertions, 0 deletions

diff --git a/library/text.tcl b/library/text.tcl
index 396ce1b..4a0e2c7 100644
--- a/library/text.tcl
+++ b/library/text.tcl
@@ -346,7 +346,16 @@ bind Text <Control-t> {
 }
 
 bind Text <<Undo>> {
+    # An Undo operation may remove the separator at the top of the Undo stack.
+    # Then the item at the top of the stack gets merged with the subsequent changes.
+    # Place separators before and after Undo to prevent this.
+    if {[%W cget -autoseparators]} {
+	%W edit separator
+    }
     catch { %W edit undo }
+    if {[%W cget -autoseparators]} {
+	%W edit separator
+    }
 }
 
 bind Text <<Redo>> {
diff --git a/tests/text.test b/tests/text.test
index 661584d..4eeb8e4 100644
--- a/tests/text.test
+++ b/tests/text.test
@@ -3238,6 +3238,22 @@ test text-25.20 {patch 1669632 (iv) - undo after <Control-backslash>} -setup {
 } -cleanup {
     destroy .top.t .top
 } -result HELLO
+test text-25.21 {patch 1669632 (vii) - <<Undo>> shall not remove separators} -setup {
+    destroy .t
+} -body {
+    text .t -undo 1
+    .t insert end "This is an example text"
+    .t edit reset
+    .t insert 1.5 "WORLD "
+    event generate .t <Control-1> -x 1 -y 1
+    .t insert insert HELLO
+    event generate .t <<Undo>>
+    .t insert insert E
+    event generate .t <<Undo>>
+    .t get 1.0 "1.0 lineend"
+} -cleanup {
+    destroy .t
+} -result "This WORLD is an example text"
 
 test text-26.1 {bug fix - 624372, ControlUtfProc long lines} {
     destroy .t