2 files changed, 8 insertions, 0 deletions

diff --git a/cgit.h b/cgit.h
index f01f6c9..6937c42 100644
--- a/cgit.h
+++ b/cgit.h
@@ -148,24 +148,25 @@ extern char *cgit_query_name;
 extern int   cgit_query_ofs;
 
 extern int htmlfd;
 
 extern int cgit_get_cmd_index(const char *cmd);
 extern struct repoinfo *cgit_get_repoinfo(const char *url);
 extern void cgit_global_config_cb(const char *name, const char *value);
 extern void cgit_repo_config_cb(const char *name, const char *value);
 extern void cgit_querystring_cb(const char *name, const char *value);
 
 extern int chk_zero(int result, char *msg);
 extern int chk_positive(int result, char *msg);
+extern int chk_non_negative(int result, char *msg);
 
 extern int hextoint(char c);
 extern char *trim_end(const char *str, char c);
 
 extern void *cgit_free_commitinfo(struct commitinfo *info);
 
 extern int cgit_diff_files(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
                            linediff_fn fn);
 
 extern void cgit_diff_tree(const unsigned char *old_sha1,
                            const unsigned char *new_sha1,
diff --git a/shared.c b/shared.c
index 1a5b866..65fc8b2 100644
--- a/shared.c
+++ b/shared.c
@@ -77,24 +77,31 @@ int chk_zero(int result, char *msg)
         if (result != 0)
                 die("%s: %s", msg, strerror(errno));
         return result;
 }
 
 int chk_positive(int result, char *msg)
 {
         if (result <= 0)
                 die("%s: %s", msg, strerror(errno));
         return result;
 }
 
+int chk_non_negative(int result, char *msg)
+{
+            if (result < 0)
+                    die("%s: %s",msg, strerror(errno));
+        return result;
+}
+
 struct repoinfo *add_repo(const char *url)
 {
         struct repoinfo *ret;
 
         if (++cgit_repolist.count > cgit_repolist.length) {
                 if (cgit_repolist.length == 0)
                         cgit_repolist.length = 8;
                 else
                         cgit_repolist.length *= 2;
                 cgit_repolist.repos = xrealloc(cgit_repolist.repos,
                                                cgit_repolist.length *
                                                sizeof(struct repoinfo));