use a local instead of reusing global AF in gvrender_polyline

There is a static global, AF, that is reused for a number of gvrender functions,
but none need to retain previous data stored in this array. This hack presumably
was from a time when allocators were much slower. Refactoring this into a local
allocation makes this function thread safe and removes the need to unnecessarily
prolong the lifetime of this allocation, thus decreasing Graphviz memory usage.
This commit introduces a -Wshadow warning about AF, but that will be removed
when we soon remove the static global.

diff --git a/lib/gvc/gvrender.c b/lib/gvc/gvrender.c
index c5a858de5ad3bfd9a6a1a3a6c73ce59182ce386f..bbbdbef32c10b8eed3d4679dbfe3a67447bb4d4e 100644 (file)
--- a/lib/gvc/gvrender.c
+++ b/lib/gvc/gvrender.c
@@ -646,12 +646,12 @@ void gvrender_polyline(GVJ_t * job, pointf * af, int n)
            if (job->flags & GVRENDER_DOES_TRANSFORM)
                gvre->polyline(job, af, n);
            else {
-               if (sizeAF < n) {
-                   sizeAF = n + 10;
-                   AF = grealloc(AF, sizeAF * sizeof(pointf));
-               }
+               pointf *AF;
+               assert(n >= 0);
+               AF = gcalloc((size_t)n, sizeof(pointf));
                gvrender_ptf_A(job, af, AF, n);
                gvre->polyline(job, AF, n);
+               free(AF);
            }
        }
     }