check cookie read for success

git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.2@557 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/program/src/rrd_open.c b/program/src/rrd_open.c
index ff68ca42cea741877f8fdbd8773aec6027fe7b22..7b1a0f1da50f333cc570ef27c5d3821e3c6b0700 100644 (file)
--- a/program/src/rrd_open.c
+++ b/program/src/rrd_open.c
@@ -101,11 +101,17 @@ rrd_open(const char *file_name, FILE **in_file, rrd_t *rrd, int rdwr)
     if ((MYVAR = malloc(sizeof(MYVART) * MYCNT)) == NULL) {\
        rrd_set_error("" #MYVAR " malloc"); \
         fclose(*in_file); \
-    return (-1); } \
+        return (-1); } \
     fread(MYVAR,sizeof(MYVART),MYCNT, *in_file); 
 
 
     MYFREAD(rrd->stat_head, stat_head_t,  1)
+    /* lets see if the first read worked */
+    if (ferror( *in_file )){
+       rrd_set_error("reading the cookie off %s faild",file_name);
+       fclose(*in_file);
+       return(-1);
+    }  
     version = atoi(rrd->stat_head->version);
 
        /* lets do some test if we are on track ... */