From 3cd6b6ecb23bbbba170be5d0b930f5f75e46d76d Mon Sep 17 00:00:00 2001
From: Joe R <joeraz5@verizon.net>
Date: Thu, 6 Oct 2022 22:50:14 -0400
Subject: [PATCH] Fixed manual undo causing false stuck notifications.

---
 pysollib/game/__init__.py | 16 +++++++++++++++-
 pysollib/move.py          | 10 ++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/pysollib/game/__init__.py b/pysollib/game/__init__.py
index 2c90ffd5..69a61578 100644
--- a/pysollib/game/__init__.py
+++ b/pysollib/game/__init__.py
@@ -3029,6 +3029,19 @@ class Game(object):
                         break
                 else:
                     redo = 1
+        # try to detect an undo move for stuck-checking
+        undo = 0
+        if len(moves.history) > 0:
+            mylen, m = len(current), moves.history[moves.index - 1]
+            if mylen == len(m):
+                for i in range(mylen):
+                    a1 = current[i]
+                    a2 = m[i]
+                    if a1.__class__ is not a2.__class__ or \
+                            a1.cmpForUndo(a2) != 0:
+                        break
+                else:
+                    undo = 1
         # add current move to history (which is a list of lists)
         if redo:
             # print "detected redo:", current
@@ -3049,7 +3062,8 @@ class Game(object):
         self.updateStatus(moves=(moves.index, self.stats.total_moves))
         self.updateMenus()
         self.updatePlayTime(do_after=0)
-        self.updateStuck()
+        if not undo:
+            self.updateStuck()
         reset_solver_dialog()
 
         return 1
diff --git a/pysollib/move.py b/pysollib/move.py
index 90129449..b585a836 100644
--- a/pysollib/move.py
+++ b/pysollib/move.py
@@ -58,6 +58,11 @@ class AtomicMove:
     def cmpForRedo(self, other):
         return -1
 
+    # Custom comparison for detecting manual undoing.
+    # Override only for move types where this is possible.
+    def cmpForUndo(self, other):
+        return -1
+
 
 # ************************************************************************
 # * Move the top N cards from a stack to another stack.
@@ -107,6 +112,11 @@ class AMoveMove(AtomicMove):
                 cmp(self.from_stack_id, other.from_stack_id) or
                 cmp(self.to_stack_id, other.to_stack_id))
 
+    def cmpForUndo(self, other):
+        return (cmp(self.ncards, other.ncards) or
+                cmp(self.from_stack_id, other.to_stack_id) or
+                cmp(self.to_stack_id, other.from_stack_id))
+
 
 # ************************************************************************
 # * Flip the top card of a stack.