From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Sat, 19 Feb 2022 18:21:02 +0000 (-0800)
Subject: diffimg: handle allocation errors
X-Git-Tag: 3.0.0~15^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=6278a805d0df78105c2ecfce156baa607a9f4521;p=graphviz

diffimg: handle allocation errors

Previously these would be ignored resulting in crashes when allocations failed.
---

diff --git a/contrib/diffimg/diffimg.c b/contrib/diffimg/diffimg.c
index 3af05d2df..52ecb98bf 100644
--- a/contrib/diffimg/diffimg.c
+++ b/contrib/diffimg/diffimg.c
@@ -33,6 +33,7 @@
 #define EX_DATAERR		65
 #define EX_NOINPUT		66
 #define EX_UNAVAILABLE	69
+#define EX_OSERR	71
 #else
 #include <sysexits.h>
 #endif
@@ -43,6 +44,15 @@
 
 static char *pstopng="gs -dNOPAUSE -sDEVICE=pngalpha -sOutputFile=- -q -";
 
+static void *xmalloc(size_t size) {
+  void *p = malloc(size);
+  if (size > 0 && p == NULL) {
+    fprintf(stderr, "Out of memory\n");
+    graphviz_exit(EX_OSERR);
+  }
+  return p;
+}
+
 static gdImagePtr imageLoad (char *filename)
 {
     FILE *f;
@@ -63,11 +73,11 @@ static gdImagePtr imageLoad (char *filename)
     }
     if (strcasecmp(ext, ".ps") == 0) {
 	ext = ".png";
-	tmp = malloc(strlen(filename) + strlen(ext) + 1);
+	tmp = xmalloc(strlen(filename) + strlen(ext) + 1);
 	strcpy(tmp,filename);
 	strcat(tmp,ext);
 	
-	cmd = malloc(strlen(pstopng) + 2 + strlen(filename) + 2 + strlen(tmp) + 1);
+	cmd = xmalloc(strlen(pstopng) + 2 + strlen(filename) + 2 + strlen(tmp) + 1);
 	strcpy(cmd,pstopng);
 	strcat(cmd," <");
 	strcat(cmd,filename);