42785: Allow redefining math function to work silently.

Previously it failed with an error message that the function
was already defined.  This is inconsistent with most other
aspects of shell usage.

2 files changed, 9 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index deac58d68..e6e1427f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2018-05-17  Peter Stephenson  <p.stephenson@samsung.com>
+
+	* 42785: Src/builtins.c: redefining a user math function should
+	silently work as with redefining other shell objects.
+
 2018-05-14  Peter Stephenson  <p.stephenson@samsung.com>
 
 	* 42297: dana: Src/params.c, Test/D06subscript.ztst: (e)
diff --git a/Src/builtin.c b/Src/builtin.c
index 931605c6e..1cba97dec 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -3199,7 +3199,7 @@ bin_functions(char *name, char **argv, Options ops, int func)
 	pflags |= PRINT_NAMEONLY;
 
     if (OPT_MINUS(ops,'M') || OPT_PLUS(ops,'M')) {
-	MathFunc p, q;
+	MathFunc p, q, prev;
 	/*
 	 * Add/remove/list function as mathematical.
 	 */
@@ -3331,15 +3331,10 @@ bin_functions(char *name, char **argv, Options ops, int func)
 	    p->maxargs = maxargs;
 
 	    queue_signals();
-	    for (q = mathfuncs; q; q = q->next) {
+	    for (q = mathfuncs, prev = NULL; q; prev = q, q = q->next) {
 		if (!strcmp(q->name, funcname)) {
-		    unqueue_signals();
-		    zwarnnam(name, "-M %s: function already exists",
-			     funcname);
-		    zsfree(p->name);
-		    zsfree(p->module);
-		    zfree(p, sizeof(struct mathfunc));
-		    return 1;
+		    removemathfunc(prev, q);
+		    break;
 		}
 	    }