From bcfa337efd51a3709d09b83db45bb057cbd817b5 Mon Sep 17 00:00:00 2001
From: apnadkarni <apnmbx-wits@yahoo.com>
Date: Mon, 16 Dec 2024 13:13:44 +0000
Subject: [PATCH] Fix [f32864af] - thread::eval hang

---
 generic/threadSpCmd.c | 5 ++++-
 tests/thread.test     | 6 ++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/generic/threadSpCmd.c b/generic/threadSpCmd.c
index 7144977..d837829 100644
--- a/generic/threadSpCmd.c
+++ b/generic/threadSpCmd.c
@@ -713,7 +713,7 @@ ThreadEvalObjCmd(
     }
 
     /*
-     * Find out wether to use the internal (recursive) mutex
+     * Find out whether to use the internal (recursive) mutex
      * or external mutex given on the command line, and lock
      * the corresponding mutex immediately.
      *
@@ -740,11 +740,13 @@ ThreadEvalObjCmd(
 	    return TCL_ERROR;
 	}
 	if (IsReadWrite(mutexPtr)) {
+            PutMutex(mutexPtr);
 	    Tcl_AppendResult(interp, "wrong mutex type, must be exclusive "
 			     "or recursive", NULL);
 	    return TCL_ERROR;
 	}
 	if (!SpMutexLock(mutexPtr)) {
+            PutMutex(mutexPtr);
 	    Tcl_AppendResult(interp, "locking the same exclusive mutex "
 			     "twice from the same thread", NULL);
 	    return TCL_ERROR;
@@ -786,6 +788,7 @@ ThreadEvalObjCmd(
 	Sp_RecursiveMutexUnlock(&evalMutex);
     } else {
 	SpMutexUnlock(mutexPtr);
+        PutMutex(mutexPtr);
     }
 
     return ret;
diff --git a/tests/thread.test b/tests/thread.test
index e8359ca..7b2cae4 100644
--- a/tests/thread.test
+++ b/tests/thread.test
@@ -1250,5 +1250,11 @@ test thread-21.16 {thread::cond - delete waited variable} {
     list $c1 $c2 $r1 $r2
 } {1 0 {condition variable is in use} {}}
 
+test thread-bug-f32864afe3 {Hang in thread::eval -lock} -body {
+    set mu [thread::mutex create]
+    thread::eval -lock $mu {}
+    thread::mutex destroy $mu ; # <- Bug f32864af hang
+} -result {}
+
 removeFile dummyForTransfer
 ::tcltest::cleanupTests