From f87029f7b13142499a37fb311a721d99bb1aecd7 Mon Sep 17 00:00:00 2001
From: Pratik Borhade <PratikPB2123>
Date: Tue, 5 Apr 2022 20:53:35 +1000
Subject: Fix T96424: Don't register undo step for empty knife cut

Prevents undo push when no cut has been made.

Reviewed By: campbellbarton

Ref D14329
---
 source/blender/editors/mesh/editmesh_knife.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/source/blender/editors/mesh/editmesh_knife.c b/source/blender/editors/mesh/editmesh_knife.c
index 64d10f7e2af..73716f6edba 100644
--- a/source/blender/editors/mesh/editmesh_knife.c
+++ b/source/blender/editors/mesh/editmesh_knife.c
@@ -4399,6 +4399,11 @@ static int knifetool_modal(bContext *C, wmOperator *op, const wmEvent *event)
         knifetool_exit(op);
         ED_workspace_status_text(C, NULL);
 
+        /* Exit early to prevent undo push for empty cuts. */
+        if (kcd->totkvert == 0) {
+          return OPERATOR_CANCELLED;
+        }
+
         return OPERATOR_FINISHED;
       case KNF_MODAL_UNDO:
         if (BLI_stack_is_empty(kcd->undostack)) {
-- 
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