From 2a6b32ce5b342becee227b724efd2719ddb58dd1 Mon Sep 17 00:00:00 2001
From: Alex Jordan <v-alexjo@microsoft.com>
Date: Thu, 7 Jul 2016 14:54:47 -0700
Subject: [PATCH] Refactored followsymlink

---
 src/libpsl-native/src/followsymlink.cpp | 35 +++++++++++++++++--------
 1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/libpsl-native/src/followsymlink.cpp b/src/libpsl-native/src/followsymlink.cpp
index d4308f2df..24a544664 100644
--- a/src/libpsl-native/src/followsymlink.cpp
+++ b/src/libpsl-native/src/followsymlink.cpp
@@ -8,6 +8,7 @@
 #include <iostream>
 #include "followsymlink.h"
 #include "issymlink.h"
+
 //! @brief Followsymlink determines target path of a sym link
 //!
 //! Followsymlink
@@ -38,26 +39,30 @@ char* FollowSymLink(const char* fileName)
 {
     errno = 0;  
 
-    // Check parameters
+    // if filename is null, return null value
     if (!fileName)
     {
         errno = ERROR_INVALID_PARAMETER;
         return NULL;
     }
 
-    char actualpath[PATH_MAX+1];
-    char* realPath = realpath(fileName, actualpath);
-    
-    /* if realPath does not return a value, continue with previous implementation of symlink*/
-    if (IsSymLink(fileName)) 
+    //if lstat in IsSymLink returns -1, path does not exist
+    if (IsSymLink(fileName) == -1)
     {
+        printf("-1 %s", fileName);
+        return NULL;
+    }
+
+    /*If the path is a symlink, the function return the absolute filepath if valid. if not valid, return null*/     
+    if (IsSymLink(fileName) == 1)
+    {
+        printf("readlink %s", fileName);
         char buffer[PATH_MAX];
         ssize_t sz = readlink(fileName, buffer, PATH_MAX);
     
         if  (sz == -1)
         {
             switch(errno)
-
             {
                 case EACCES:
                     errno = ERROR_ACCESS_DENIED;
@@ -89,16 +94,23 @@ char* FollowSymLink(const char* fileName)
                 default:
                     errno = ERROR_INVALID_FUNCTION;
                 }
+
                 return NULL;
         }
 
         buffer[sz] = '\0';
         return strndup(buffer, sz + 1);
-    }
-    
-/*else realpath returned a valid resolved path*/
+     
+    } 
+
+    /*else the path is not a symlink - but attempt to resolve*/
     else 
     {
+        printf("realpath %s", fileName);
+        //Attempt to resolve with the absolute filepath
+        char actualpath[PATH_MAX+1];
+        char* realPath = realpath(fileName, actualpath);
+
         if  (sizeof(realPath) == -1)
         {
             switch(errno)
@@ -133,9 +145,10 @@ char* FollowSymLink(const char* fileName)
                 default:
                     errno = ERROR_INVALID_FUNCTION;
                 }
+
                 return NULL;
         }
 
-        return strndup(realPath, strlen(realPath) + 1 );
+       return strndup(realPath, strlen(realPath) + 1 );
     }
 }