Index: .github/workflows/linux-build.yml
==================================================================
--- .github/workflows/linux-build.yml
+++ .github/workflows/linux-build.yml
@@ -3,10 +3,11 @@
   push:
     branches:
     - "main"
     - "core-8-branch"
     - "core-8-6-branch"
+    - "bug-ab839efc5f"
     tags:
     - "core-**"
 permissions:
   contents: read
 defaults:

Index: .github/workflows/mac-build.yml
==================================================================
--- .github/workflows/mac-build.yml
+++ .github/workflows/mac-build.yml
@@ -3,10 +3,11 @@
   push:
     branches:
     - "main"
     - "core-8-branch"
     - "core-8-6-branch"
+    - "bug-ab839efc5f"
     tags:
     - "core-**"
 permissions:
   contents: read
 env:

Index: .github/workflows/win-build.yml
==================================================================
--- .github/workflows/win-build.yml
+++ .github/workflows/win-build.yml
@@ -3,10 +3,11 @@
   push:
     branches:
     - "main"
     - "core-8-branch"
     - "core-8-6-branch"
+    - "bug-ab839efc5f"
     tags:
     - "core-**"
 permissions:
   contents: read
 env:

Index: generic/tkText.c
==================================================================
--- generic/tkText.c
+++ generic/tkText.c
@@ -5056,10 +5056,14 @@
     int status;
 
     if (!textPtr->sharedTextPtr->undo) {
 	return TCL_OK;
     }
+
+    if (textPtr->sharedTextPtr->autoSeparators) {
+	TkUndoInsertUndoSeparator(textPtr->sharedTextPtr->undoStack);
+    }
 
     /*
      * Turn off the undo feature while we revert a compound action, setting
      * the dirty handling mode to undo for the duration (unless it is
      * 'fixed').
@@ -5074,10 +5078,14 @@
 
     if (textPtr->sharedTextPtr->dirtyMode != TK_TEXT_DIRTY_FIXED) {
 	textPtr->sharedTextPtr->dirtyMode = TK_TEXT_DIRTY_NORMAL;
     }
     textPtr->sharedTextPtr->undo = 1;
+
+    if (textPtr->sharedTextPtr->autoSeparators) {
+	TkUndoInsertUndoSeparator(textPtr->sharedTextPtr->undoStack);
+    }
 
     return status;
 }
 
 /*

Index: tests/text.test
==================================================================
--- tests/text.test
+++ tests/text.test
@@ -6965,10 +6965,25 @@
     .t edit reset
     update ; lappend res $nbUS
 } -cleanup {
     destroy .t
 } -result {0 0 1 2 3 4 4 5 6 6 7 8 8 9}
+test text-27.26 {bug ab839efc5f - .text edit undo inserts separators} -setup {
+    destroy .t
+} -body {
+    text .t -undo 1
+    .t insert 1.0 "1. 123 5 789012  LINE-1\n2.\n3. 123 5 789012  LINE-3\n"
+    .t tag add sel 3.0 3.end
+    .t delete sel.first sel.last
+    .t edit undo
+    .t tag add sel 3.0 3.end
+    .t delete sel.first sel.last
+    .t edit undo
+    .t get 3.0 3.end
+} -cleanup {
+    destroy .t
+} -result {3. 123 5 789012  LINE-3}
 
 
 test text-28.1 {bug fix - 624372, ControlUtfProc long lines} -body {
     pack [text .t -wrap none]
     .t insert end [string repeat "\1" 500]