swaybar: fix loading of malformed icon theme

If the icon index.theme contained a key-value pair without a preceding
group header, entry_handler() would be called with a zero pointer and
lead to a segfault.
Set the error flag and break on such malformed files.

1 files changed, 4 insertions, 0 deletions

diff --git a/swaybar/tray/icon.c b/swaybar/tray/icon.c
index 2276e36d..8587f3f7 100644
--- a/swaybar/tray/icon.c
+++ b/swaybar/tray/icon.c
@@ -243,6 +243,10 @@ static struct icon_theme *read_theme_file(char *basedir, char *theme_name) {
                         free(group);
                         group = strdup(&line[1]);
                 } else { // key-value pair
+                        if (!group) {
+                                error = true;
+                                break;
+                        }
                         // check well-formed
                         int eok = 0;
                         for (; isalnum(line[eok]) || line[eok] == '-'; ++eok) {} // TODO locale?