allow to restore xml files with zero row rras ... this is a degenerated case

that does not occure in the wild, as rrdtool prevents the creation of such
rrd files. But rrdtool restore 1.3 did allows to create them via restore.
Now this is possible again. Fix for #310.

git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@2212 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/src/rrd_restore.c b/src/rrd_restore.c
index fde83ae64abf7b7e5ed6b318629c915ade429fe9..39148e89e80dc490bfd2ab946b91029d02448fba 100644 (file)
--- a/src/rrd_restore.c
+++ b/src/rrd_restore.c
@@ -788,7 +788,7 @@ static int parse_tag_rra(
 
     /* All space successfully allocated, increment number of RRAs. */
     rrd->stat_head->rra_cnt++;
-
+    
     status = 0;
     while ((element = get_xml_element(reader)) != NULL){
         if (xmlStrcasecmp(element, (const xmlChar *) "cf") == 0)
@@ -827,7 +827,7 @@ static int parse_tag_rra(
                 return status;
         }
         else if (xmlStrcasecmp(element,(const xmlChar *) "/rra") == 0){
-            xmlFree(element);            
+            xmlFree(element);
             return status;
         }  /* }}} */        
        else {
@@ -1180,15 +1180,16 @@ static int write_file(
         unsigned long num_rows = rrd->rra_def[i].row_cnt;
         unsigned long cur_row = rrd->rra_ptr[i].cur_row;
         unsigned long ds_cnt = rrd->stat_head->ds_cnt;
+        if (num_rows > 0){
+            fwrite(rrd->rrd_value +
+                (rra_offset + num_rows - 1 - cur_row) * ds_cnt,
+                sizeof(rrd_value_t), (cur_row + 1) * ds_cnt, fh);
 
-        fwrite(rrd->rrd_value +
-               (rra_offset + num_rows - 1 - cur_row) * ds_cnt,
-               sizeof(rrd_value_t), (cur_row + 1) * ds_cnt, fh);
-
-        fwrite(rrd->rrd_value + rra_offset * ds_cnt,
-               sizeof(rrd_value_t), (num_rows - 1 - cur_row) * ds_cnt, fh);
+            fwrite(rrd->rrd_value + rra_offset * ds_cnt,
+                sizeof(rrd_value_t), (num_rows - 1 - cur_row) * ds_cnt, fh);
 
-        rra_offset += num_rows;
+            rra_offset += num_rows;
+        }
     }
 
     /* lets see if we had an error */