cmd_hide_edge_borders: add missing arg count check

This adds the missing argument count check after the --i3 flag
processing in cmd_hide_edge_borders. Without the check,
`hide_edge_borders --i3` would result in a SIGSEGV instead of a syntax
error. There are some minor adjustments to make it so nothing gets
altered if this check fails

1 files changed, 11 insertions, 5 deletions

diff --git a/sway/commands/hide_edge_borders.c b/sway/commands/hide_edge_borders.c
index ac439cc0..f69bece1 100644
--- a/sway/commands/hide_edge_borders.c
+++ b/sway/commands/hide_edge_borders.c
@@ -4,17 +4,23 @@
 #include "sway/tree/view.h"
 
 struct cmd_results *cmd_hide_edge_borders(int argc, char **argv) {
+        const char *expected_syntax = "Expected 'hide_edge_borders [--i3] "
+                "none|vertical|horizontal|both|smart|smart_no_gaps";
+
         struct cmd_results *error = NULL;
         if ((error = checkarg(argc, "hide_edge_borders", EXPECTED_AT_LEAST, 1))) {
                 return error;
         }
 
+        bool hide_lone_tab = false;
         if (strcmp(*argv, "--i3") == 0) {
-                config->hide_lone_tab = true;
+                hide_lone_tab = true;
                 ++argv;
                 --argc;
-        } else {
-                config->hide_lone_tab = false;
+        }
+
+        if (!argc) {
+                return cmd_results_new(CMD_INVALID, expected_syntax);
         }
 
         if (strcmp(argv[0], "none") == 0) {
@@ -30,9 +36,9 @@ struct cmd_results *cmd_hide_edge_borders(int argc, char **argv) {
         } else if (strcmp(argv[0], "smart_no_gaps") == 0) {
                 config->hide_edge_borders = E_SMART_NO_GAPS;
         } else {
-                return cmd_results_new(CMD_INVALID, "Expected 'hide_edge_borders "
-                                "[--i3] <none|vertical|horizontal|both|smart|smart_no_gaps>'");
+                return cmd_results_new(CMD_INVALID, expected_syntax);
         }
+        config->hide_lone_tab = hide_lone_tab;
         config->saved_edge_borders = config->hide_edge_borders;
 
         arrange_root();