merge trunk

2 files changed, 22 insertions, 18 deletions

diff --git a/generic/tcl.h b/generic/tcl.h
index 162983b..f7d54b5 100644
--- a/generic/tcl.h
+++ b/generic/tcl.h
@@ -681,10 +681,7 @@ typedef struct Tcl_Obj {
  * whether an object is shared (i.e. has reference count > 1). Note: clients
  * should use Tcl_DecrRefCount() when they are finished using an object, and
  * should never call TclFreeObj() directly. TclFreeObj() is only defined and
- * made public in tcl.h to support Tcl_DecrRefCount's macro definition. Note
- * also that Tcl_DecrRefCount() refers to the parameter "obj" twice. This
- * means that you should avoid calling it with an expression that is expensive
- * to compute or has side effects.
+ * made public in tcl.h to support Tcl_DecrRefCount's macro definition.
  */
 
 void		Tcl_IncrRefCount(Tcl_Obj *objPtr);
@@ -2310,7 +2307,12 @@ TCLAPI void		Tcl_GetMemoryInfo(Tcl_DString *dsPtr);
      * http://c2.com/cgi/wiki?TrivialDoWhileLoop
      */
 #   define Tcl_DecrRefCount(objPtr) \
-	do { if (--(objPtr)->refCount <= 0) TclFreeObj(objPtr); } while(0)
+	do { \
+	    Tcl_Obj *_objPtr = (objPtr); \
+	    if (_objPtr->refCount-- < 2) { \
+		TclFreeObj(_objPtr); \
+	    } \
+	} while(0)
 #   define Tcl_IsShared(objPtr) \
 	((objPtr)->refCount > 1)
 #endif
diff --git a/generic/tclInt.h b/generic/tclInt.h
index 0efb1b6..7c699c9 100644
--- a/generic/tclInt.h
+++ b/generic/tclInt.h
@@ -3934,24 +3934,26 @@ typedef const char *TclDTraceStr;
  * Invalidate the string rep first so we can use the bytes value for our
  * pointer chain, and signal an obj deletion (as opposed to shimmering) with
  * 'length == -1'.
- * Use empty 'if ; else' to handle use in unbraced outer if/else conditions.
  */
 
 # define TclDecrRefCount(objPtr) \
-    if (--(objPtr)->refCount > 0) ; else { \
-	if (!(objPtr)->typePtr || !(objPtr)->typePtr->freeIntRepProc) { \
-	    TCL_DTRACE_OBJ_FREE(objPtr); \
-	    if ((objPtr)->bytes \
-		    && ((objPtr)->bytes != tclEmptyStringRep)) { \
-		ckfree((char *) (objPtr)->bytes); \
+    do { \
+	Tcl_Obj *_objPtr = (objPtr); \
+	if (_objPtr->refCount-- < 2) { \
+	    if (!_objPtr->typePtr || !_objPtr->typePtr->freeIntRepProc) { \
+		TCL_DTRACE_OBJ_FREE(_objPtr); \
+		if (_objPtr->bytes \
+			&& (_objPtr->bytes != tclEmptyStringRep)) { \
+		    ckfree((char *) _objPtr->bytes); \
+		} \
+		_objPtr->length = -1; \
+		TclFreeObjStorage(_objPtr); \
+		TclIncrObjsFreed(); \
+	    } else { \
+		TclFreeObj(_objPtr); \
 	    } \
-	    (objPtr)->length = -1; \
-	    TclFreeObjStorage(objPtr); \
-	    TclIncrObjsFreed(); \
-	} else { \
-	    TclFreeObj(objPtr); \
 	} \
-    }
+    } while(0)
 
 #if defined(PURIFY)