cgraph: replace unchecked agxbuf allocations with alloc helpers

These allocations are at the core of some work Graphviz does and were not
checked for failure. This change swaps confusing crashes on out-of-memory for a
more graceful exit.

diff --git a/lib/cgraph/agxbuf.c b/lib/cgraph/agxbuf.c
index 627e02b3f785c8553951af33d6a00f534de2f2cd..eef13d6321902a912757365a845ab2311f766adf 100644 (file)
--- a/lib/cgraph/agxbuf.c
+++ b/lib/cgraph/agxbuf.c
@@ -14,8 +14,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <cgraph/agxbuf.h>
-
-#define N_GNEW(n,t)     calloc((n),sizeof(t))
+#include <cgraph/alloc.h>
 
 /* agxbinit:
  * Assume if init is non-null, hint = sizeof(init[])
@@ -29,7 +28,7 @@ void agxbinit(agxbuf * xb, unsigned int hint, unsigned char *init)
        if (hint == 0)
            hint = BUFSIZ;
        xb->dyna = 1;
-       xb->buf = N_GNEW(hint, unsigned char);
+       xb->buf = gv_calloc(hint, sizeof(unsigned char));
     }
     xb->eptr = xb->buf + hint;
     xb->ptr = xb->buf;
@@ -52,9 +51,9 @@ void agxbmore(agxbuf * xb, size_t ssz)
        nsize = size + ssz;
     cnt = (size_t) (xb->ptr - xb->buf);
     if (xb->dyna) {
-       nbuf = realloc(xb->buf, nsize);
+       nbuf = gv_recalloc(xb->buf, size, nsize, sizeof(unsigned char));
     } else {
-       nbuf = N_GNEW(nsize, unsigned char);
+       nbuf = gv_calloc(nsize, sizeof(unsigned char));
        memcpy(nbuf, xb->buf, cnt);
        xb->dyna = 1;
     }