make friend add fail if friend is in the block list

src/friendlist.c

@@ -1240,6 +1240,26 @@ Tox_Connection get_friend_connection_status(uint32_t friendnumber)
     return Friends.list[friendnumber].connection_status;
 }
 
+/*
+ * Returns true if friend associated with `public_key` is in the block list.
+ *
+ * `public_key` must be at least TOX_PUBLIC_KEY_SIZE bytes.
+ */
+bool friend_is_blocked(const char *public_key)
+{
+    for (size_t i = 0; i < Blocked.max_idx; ++i) {
+        if (!Blocked.list[i].active) {
+            continue;
+        }
+
+        if (memcmp(public_key, Blocked.list[i].pub_key, TOX_PUBLIC_KEY_SIZE) == 0) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
 ToxWindow *new_friendlist(void)
 {
     ToxWindow *ret = calloc(1, sizeof(ToxWindow));

src/friendlist.h

@@ -93,4 +93,11 @@ Tox_Connection get_friend_connection_status(uint32_t friendnumber);
 /* sorts friendlist_index first by connection status then alphabetically */
 void sort_friendlist_index(void);
 
+/*
+ * Returns true if friend associated with `public_key` is in the block list.
+ *
+ * `public_key` must be at least TOX_PUBLIC_KEY_SIZE bytes.
+ */
+bool friend_is_blocked(const char *public_key);
+
 #endif /* end of include guard: FRIENDLIST_H */

src/global_commands.c

@@ -133,7 +133,7 @@ void cmd_add_helper(ToxWindow *self, Tox *m, const char *id_bin, const char *msg
 
         /* fallthrough */
         default:
-            errmsg = "Faile to add friend: Unknown error.";
+            errmsg = "Failed to add friend: Unknown error.";
             break;
     }
 
@@ -193,6 +193,11 @@ void cmd_add(WINDOW *window, ToxWindow *self, Tox *m, int argc, char (*argv)[MAX
             id_bin[i] = x;
         }
 
+        if (friend_is_blocked(id_bin)) {
+            line_info_add(self, NULL, NULL, NULL, SYS_MSG, 0, 0, "Friend is in your block list.");
+            return;
+        }
+
         cmd_add_helper(self, m, id_bin, msg);
     } else {    /* assume id is a username@domain address and do http name server lookup */
         name_lookup(self, m, id_bin, id, msg);