diff --git a/debian/changelog b/debian/changelog
index 2e93b35a..c3340407 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -5,6 +5,7 @@ shadow (1:4.1.2-1) experimental; urgency=low
     - Updated patches:
       + debian/patches/431_su_uid_0_not_root
       + debian/patches/463_login_delay_obeys_to_PAM
+      + debian/patches/579_chowntty_debug
   * debian/control: changed the "Replaces" on manpages-zh to a versioned
     one on 1.5.1-1
   * debian/control: drop all Replaces on manpages-* when the version is
diff --git a/debian/patches/579_chowntty_debug b/debian/patches/579_chowntty_debug
index 5b4e9f6f..2844e18b 100644
--- a/debian/patches/579_chowntty_debug
+++ b/debian/patches/579_chowntty_debug
@@ -25,26 +25,26 @@ Index: shadow-4.1.0/libmisc/chowntty.c
  /*
   * is_my_tty -- determine if "tty" is the same as TTY stdin is using
   */
-@@ -47,12 +48,31 @@
+@@ -47,13 +48,31 @@
  {
  	struct stat by_name, by_fd;
  
--	if (stat (tty, &by_name) || fstat (0, &by_fd))
-+	if (stat (tty, &by_name)) {
+-	if ((stat (tty, &by_name) != 0) || (fstat (0, &by_fd) != 0)) {
++	if (stat (tty, &by_name) != 0) {
 +		/* Can use neither strerror() nor "%m" sequence -- first
 +		 * is locale-dependent (while SYSLOG isn't) and for second
 +		 * the SYSLOG macro isn't errno-transparent.  --xrgtn */
 +		int e = errno;
 +		SYSLOG ((LOG_WARN, "can't stat(`%s'): errno %i\n", tty, e));
- 		return 0;
-+	}
+ 		return false;
+ 	}
  
--	if (by_name.st_rdev != by_fd.st_rdev)
-+	if (fstat (0, &by_fd)) {
+-	if (by_name.st_rdev != by_fd.st_rdev) {
++	if (fstat (0, &by_fd) != 0) {
 +		int e = errno;
 +		SYSLOG ((LOG_WARN, "can't fstat(stdin): errno %i\n", e));
- 		return 0;
--	else
+ 		return false;
+-	} else {
 +	}
 +
 +	if (by_name.st_rdev != by_fd.st_rdev) {
@@ -55,8 +55,8 @@ Index: shadow-4.1.0/libmisc/chowntty.c
 +			  * which are GNU extn */
 +			 major(by_name.st_rdev), minor(by_name.st_rdev),
 +			 major(by_fd.st_rdev), minor(by_fd.st_rdev)));
-+		return 0;
-+	} else
- 		return 1;
++		return false;
++	} else {
+ 		return true;
+ 	}
  }
-