From 7b4164d3bad6d9301b20d670d9a4e121d04b5dd1 Mon Sep 17 00:00:00 2001
From: TapTap <taptap.programming@gmail.com>
Date: Thu, 3 Sep 2026 22:14:47 +0200
Subject: [PATCH] fix: accept numeric chmod special bits

---
 src/shared/chmod.c      |  4 ++--
 tests/test_client_cli.c | 12 ++++++++++++
 tests/test_metadata.c   |  9 +++++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/shared/chmod.c b/src/shared/chmod.c
index 058d80b..bfea77b 100644
--- a/src/shared/chmod.c
+++ b/src/shared/chmod.c
@@ -62,12 +62,12 @@ bool chmod_apply(mode_t mode, const char* spec, mode_t* result) {
   for (size_t i = 0; i < length && numeric; i++)
     numeric = spec[i] >= '0' && spec[i] <= '7';
   if (numeric) {
-    if (length < 3 || (length == 4 && spec[0] != '0'))
+    if (length == 0 || length > 4)
       return false;
     mode_t parsed = 0;
     for (size_t i = 0; i < length; i++)
       parsed = (mode_t)((parsed << 3) | (spec[i] - '0'));
-    *result = (*result & ~07777) | parsed;
+    *result = parsed;
     return true;
   }
 
diff --git a/tests/test_client_cli.c b/tests/test_client_cli.c
index 311d28f..b6e4339 100644
--- a/tests/test_client_cli.c
+++ b/tests/test_client_cli.c
@@ -196,6 +196,17 @@ static void test_parse_args_chmod() {
   config_delete(cfg);
 }
 
+static void test_parse_args_numeric_chmod() {
+  Config* cfg = config_create();
+  char* argv[] = {"fastsync", "--chmod", "7777", "/src", "/dst"};
+  int positional_args[2];
+  int positional_count = 0;
+  EXPECT_EQ_INT(parse_args(cfg, 5, argv, positional_args, &positional_count), 0);
+  EXPECT_EQ_STR(cfg->chmod_spec, "7777");
+  EXPECT_TRUE(cfg->use_metadata);
+  config_delete(cfg);
+}
+
 static void test_parse_args_rejects_invalid_chmod() {
   Config* cfg = config_create();
   char* argv[] = {"fastsync", "--chmod=a+X", "/src", "/dst"};
@@ -377,6 +388,7 @@ void test_client_cli() {
   test_parse_args_version();
   test_parse_args_valid_port();
   test_parse_args_chmod();
+  test_parse_args_numeric_chmod();
   test_parse_args_rejects_invalid_chmod();
   test_parse_args_invalid_port();
   test_parse_args_non_numeric_port();
diff --git a/tests/test_metadata.c b/tests/test_metadata.c
index 4933e58..36f81cd 100644
--- a/tests/test_metadata.c
+++ b/tests/test_metadata.c
@@ -151,8 +151,17 @@ static void test_chmod_changes() {
   EXPECT_EQ_INT(result, 0644);
   EXPECT_TRUE(chmod_apply(0644, "a+x", &result));
   EXPECT_EQ_INT(result, 0755);
+  result = 0777;
+  EXPECT_TRUE(chmod_apply(0777, "0000", &result));
+  EXPECT_EQ_INT(result, 0000);
+  result = 0777;
+  EXPECT_TRUE(chmod_apply(0777, "7777", &result));
+  EXPECT_EQ_INT(result, 07777);
+  result = 0777;
   EXPECT_TRUE(chmod_apply(0777, "755", &result));
   EXPECT_EQ_INT(result, 0755);
+  EXPECT_FALSE(chmod_apply(0777, "888", &result));
+  EXPECT_FALSE(chmod_apply(0777, "10000", &result));
   EXPECT_FALSE(chmod_apply(0777, "a+X", &result));
   EXPECT_FALSE(chmod_apply(0777, "a+r,", &result));
 }