Don't panic if Tcl_ConvertToType is called for a type that doesn't have a setFromAnyProc, create a proper error message.

2 files changed, 11 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 117086f..2036b9c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2013-02-26  Jan Nijtmans  <nijtmans@users.sf.net>
+
+	* generic/tclObj.c: Don't panic if Tcl_ConvertToType is called for a
+	type that doesn't have a setFromAnyProc, create a proper error message.
+
 2013-02-25  Donal K. Fellows  <dkf@users.sf.net>
 
 	* tests/binary.test (binary-41.*): [Bug 3605721]: Test independence
diff --git a/generic/tclObj.c b/generic/tclObj.c
index f2ec565..a40a29d 100644
--- a/generic/tclObj.c
+++ b/generic/tclObj.c
@@ -1005,7 +1005,12 @@ Tcl_ConvertToType(
      */
 
     if (typePtr->setFromAnyProc == NULL) {
-	Tcl_Panic("may not convert object to type %s", typePtr->name);
+	if (interp) {
+	    Tcl_SetObjResult(interp, Tcl_ObjPrintf(
+		    "can't convert value to type %s", typePtr->name));
+	    Tcl_SetErrorCode(interp, "TCL", "API_ABUSE", NULL);
+	}
+	return TCL_ERROR;
     }
 
     return typePtr->setFromAnyProc(interp, objPtr);