expr: allow existing multiple argument support with --compat

Some users may not be ready to immediately move to the single-argument
expr, so provide a --compat option to configure to support the
previous behaviour as a transition strategy.

Signed-off-by: Steve Bennett <steveb@workware.net.au>

1 files changed, 23 insertions, 3 deletions

diff --git a/jim.c b/jim.c
index 64f47bd..cfc0f8f 100644
--- a/jim.c
+++ b/jim.c
@@ -13598,11 +13598,31 @@ static int Jim_UplevelCoreCommand(Jim_Interp *interp, int argc, Jim_Obj *const *
 /* [expr] */
 static int Jim_ExprCoreCommand(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 {
+    int retcode;
+
     if (argc == 2) {
-        return Jim_EvalExpression(interp, argv[1]);
+        retcode = Jim_EvalExpression(interp, argv[1]);
     }
-    Jim_WrongNumArgs(interp, 1, argv, "expression");
-    return JIM_ERR;
+#ifndef JIM_COMPAT
+    else {
+        Jim_WrongNumArgs(interp, 1, argv, "expression");
+        retcode = JIM_ERR;
+    }
+#else
+    else if (argc > 2) {
+        Jim_Obj *objPtr;
+
+        objPtr = Jim_ConcatObj(interp, argc - 1, argv + 1);
+        Jim_IncrRefCount(objPtr);
+        retcode = Jim_EvalExpression(interp, objPtr);
+        Jim_DecrRefCount(interp, objPtr);
+    }
+    else {
+        Jim_WrongNumArgs(interp, 1, argv, "expression ?...?");
+        return JIM_ERR;
+    }
+#endif
+    return retcode;
 }
 
 /* [break] */