Re: memory leaks report

[Peter Stephenson <pws@csr.com>]

Felix Rosencrantz wrote:
> V01zmodload.ztst:
> This is a new leak:
> 4 bytes in 1 blocks are definitely lost in loss record 1 of 19
>    at  malloc (vg_replace_malloc.c:153)
>    by  zalloc (mem.c:490)
>    by  ztrdup (string.c:52)
>    by  add_automathfunc (module.c:2118)
>    by  bin_zmodload_math (module.c:1397)
>    by  bin_zmodload (module.c:1005)

This was easy to track down, but in the process I discovered that
`zmodload -af' is fatally flawed: you can't autoload more than one
function from the same library, since it complains about replacing
autoloadable math functions other than the one that triggered module
loading.  Since autoloading one math function is hardly worth it, and
since there is only one math library, it rendered the feature useless.
This seems to fix it.  We need more tests for autoloading.


Index: Src/module.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/module.c,v
retrieving revision 1.13
diff -u -r1.13 module.c
--- Src/module.c	11 Mar 2004 14:27:10 -0000	1.13
+++ Src/module.c	18 Mar 2004 12:08:23 -0000
@@ -2039,6 +2039,19 @@
 MathFunc mathfuncs;
 
 /**/
+static void removemathfunc(MathFunc previous, MathFunc current)
+{
+    if (previous)
+	previous->next = current->next;
+    else
+	mathfuncs = current->next;
+
+    zsfree(current->name);
+    zsfree(current->module);
+    zfree(current, sizeof(*current));
+}
+
+/**/
 MathFunc
 getmathfunc(char *name, int autol)
 {
@@ -2049,13 +2062,7 @@
 	    if (autol && p->module) {
 		char *n = dupstring(p->module);
 
-		if (q)
-		    q->next = p->next;
-		else
-		    mathfuncs = p->next;
-
-		zsfree(p->module);
-		zfree(p, sizeof(*p));
+		removemathfunc(q, p);
 
 		load_module(n);
 
@@ -2071,14 +2078,22 @@
 mod_export int
 addmathfunc(MathFunc f)
 {
-    MathFunc p;
+    MathFunc p, q = NULL;
 
     if (f->flags & MFF_ADDED)
 	return 1;
 
-    for (p = mathfuncs; p; p = p->next)
-	if (!strcmp(f->name, p->name))
+    for (p = mathfuncs; p; q = p, p = p->next)
+	if (!strcmp(f->name, p->name)) {
+	    if (p->module) {
+		/*
+		 * Autoloadable, replace.
+		 */
+		removemathfunc(q, p);
+		break;
+	    }
 	    return 1;
+	}
 
     f->flags |= MFF_ADDED;
     f->next = mathfuncs;

-- 
Peter Stephenson <pws@csr.com>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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