From d8013e48bb43d8c78eba98b2fae3bc6f6cb90984 Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@courtesan.com>
Date: Tue, 7 Jun 1994 23:21:23 +0000
Subject: [PATCH] fix bug where /dirname would return NULL

---
 realpath.c      | 11 +++++++++--
 sudo_realpath.c | 11 +++++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/realpath.c b/realpath.c
index 42acf242d..97b6f461e 100644
--- a/realpath.c
+++ b/realpath.c
@@ -163,12 +163,19 @@ char * realpath(old, new)
 	errno = ENOTDIR;
 	return(realpath_ret(NULL, cwd));
     }
+
     *(temp++) = '\0';
     (void) strcpy(buf, temp);
 
+    /* if the last '/' is the first char in new we need to preserve it */
+    if (new[0] == '\0') {
+	new[0] = '/';
+	new[1] = '\0';
+    }
+
     /*
-     * chdir() to new and go a getcwd() to find real path
-     * then append buf (last component of the path) and return.
+     * chdir() to new and go a getcwd() to find real path then
+     * append buf * (last component of the path) and return.
      */
     if (chdir(new))
 	return(realpath_ret(NULL, cwd));
diff --git a/sudo_realpath.c b/sudo_realpath.c
index 42acf242d..97b6f461e 100644
--- a/sudo_realpath.c
+++ b/sudo_realpath.c
@@ -163,12 +163,19 @@ char * realpath(old, new)
 	errno = ENOTDIR;
 	return(realpath_ret(NULL, cwd));
     }
+
     *(temp++) = '\0';
     (void) strcpy(buf, temp);
 
+    /* if the last '/' is the first char in new we need to preserve it */
+    if (new[0] == '\0') {
+	new[0] = '/';
+	new[1] = '\0';
+    }
+
     /*
-     * chdir() to new and go a getcwd() to find real path
-     * then append buf (last component of the path) and return.
+     * chdir() to new and go a getcwd() to find real path then
+     * append buf * (last component of the path) and return.
      */
     if (chdir(new))
 	return(realpath_ret(NULL, cwd));