fix resource leakage in gv2gml

This addresses the following Coverity warning:

  Error: RESOURCE_LEAK (CWE-772): [#def57]
  graphviz-2.40.1/cmd/tools/gv2gml.c:713: alloc_fn: Storage is returned from allocation function "openFile".
  graphviz-2.40.1/cmd/tools/gv2gml.c:666:5: alloc_fn: Storage is returned from allocation function "fopen".
  graphviz-2.40.1/cmd/tools/gv2gml.c:666:5: var_assign: Assigning: "fp" = "fopen(name, mode)".
  graphviz-2.40.1/cmd/tools/gv2gml.c:677:5: return_alloc: Returning allocated memory "fp".
  graphviz-2.40.1/cmd/tools/gv2gml.c:713: var_assign: Assigning: "outFile" = storage returned from "openFile(optarg, "w")".
  graphviz-2.40.1/cmd/tools/gv2gml.c:713: overwrite_var: Overwriting "outFile" in "outFile = openFile(optarg, "w")" leaks the storage that "outFile" points to.
  #  711|     switch (c) {
  #  712|     case 'o':
  #  713|->       outFile = openFile(optarg, "w");
  #  714|         break;
  #  715|     case ':':

Related to #1464.

diff --git a/cmd/tools/gv2gml.c b/cmd/tools/gv2gml.c
index 9ce6e0109b2e6472f5e002a09ebcdc19c4289221..75c445e0de8825e2a1374a76ae7307feafdbec9c 100644 (file)
--- a/cmd/tools/gv2gml.c
+++ b/cmd/tools/gv2gml.c
@@ -704,6 +704,8 @@ static void initargs(int argc, char **argv)
     while ((c = getopt(argc, argv, ":o:")) != -1) {
        switch (c) {
        case 'o':
+           if (outFile != NULL)
+               fclose(outFile);
            outFile = openFile(optarg, "w");
            break;
        case ':':