[PATCH] BUG/MEDIUM: init: segfault if global._51d_property_names is not initialized

[Dragan Dosen]

When using the "51d" converter without specifying the list of 51Degrees
properties to detect (see parameter "51degrees-property-name-list"), the
"global._51d_property_names" could be left uninitialized which will lead to
segfault during init.
---
 src/haproxy.c |   23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/haproxy.c b/src/haproxy.c
index d45914f..c73d2e0 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -186,6 +186,9 @@ struct global global = {
                .separator = '|',
        },
 #endif
+#ifdef USE_51DEGREES
+       ._51d_property_names = LIST_HEAD_INIT(global._51d_property_names),
+#endif
        /* others NULL OK */
 };
 
@@ -548,7 +551,7 @@ void init(int argc, char **argv)
 #ifdef USE_51DEGREES
        int i = 0;
        struct _51d_property_names *name;
-       char **_51d_property_list;
+       char **_51d_property_list = NULL;
        fiftyoneDegreesDataSetInitStatus _51d_dataset_status = 
DATA_SET_INIT_STATUS_NOT_SET;
 #endif
 
@@ -1099,14 +1102,16 @@ void init(int argc, char **argv)
                exit(1);
 
 #ifdef USE_51DEGREES
-       i = 0;
-       list_for_each_entry(name, &global._51d_property_names, list)
-               ++i;
-       _51d_property_list = calloc(i, sizeof(char *));
-
-       i = 0;
-       list_for_each_entry(name, &global._51d_property_names, list)
-               _51d_property_list[i++] = name->name;
+       if (!LIST_ISEMPTY(&global._51d_property_names)) {
+               i = 0;
+               list_for_each_entry(name, &global._51d_property_names, list)
+                       ++i;
+               _51d_property_list = calloc(i, sizeof(char *));
+
+               i = 0;
+               list_for_each_entry(name, &global._51d_property_names, list)
+                       _51d_property_list[i++] = name->name;
+       }
 
 #ifdef FIFTYONEDEGREES_H_TRIE_INCLUDED
        _51d_dataset_status = 
fiftyoneDegreesInitWithPropertyArray(global._51d_data_file_path, 
_51d_property_list, i);
-- 
1.7.9.5