Fix [f32864af] - thread::eval hang

Author: apnadkarni

generic/threadSpCmd.c

@@ -709,7 +709,7 @@ 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.
      *
@@ -736,11 +736,13 @@ ThreadEvalObjCmd(
 	    return TCL_ERROR;
 	}
 	if (IsReadWrite(mutexPtr)) {
+            PutMutex(mutexPtr);
 	    Tcl_AppendResult(interp, "wrong mutex type, must be exclusive "
 			     "or recursive", (void *)NULL);
 	    return TCL_ERROR;
 	}
 	if (!SpMutexLock(mutexPtr)) {
+            PutMutex(mutexPtr);
 	    Tcl_AppendResult(interp, "locking the same exclusive mutex "
 			     "twice from the same thread", (void *)NULL);
 	    return TCL_ERROR;
@@ -782,6 +784,7 @@ ThreadEvalObjCmd(
 	Sp_RecursiveMutexUnlock(&evalMutex);
     } else {
 	SpMutexUnlock(mutexPtr);
+        PutMutex(mutexPtr);
     }
 
     return ret;

tests/thread.test

@@ -1263,6 +1263,11 @@ test thread-22.1  {thread::send -command} {
     set result
 } hello
 
+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