diff --git a/mozilla/xpcom/io/nsDirectoryService.cpp b/mozilla/xpcom/io/nsDirectoryService.cpp
index 973f760fe55..46307e57da6 100644
--- a/mozilla/xpcom/io/nsDirectoryService.cpp
+++ b/mozilla/xpcom/io/nsDirectoryService.cpp
@@ -252,31 +252,29 @@ nsDirectoryService::GetCurrentProcessDirectory(nsILocalFile** aFile)
 
     if (moz5)
     {
-        localFile->InitWithNativePath(nsDependentCString(moz5));
-        localFile->Normalize();
-        *aFile = localFile;
-        return NS_OK;
-    }
-    else
-    {
-#if defined(DEBUG)
-        static PRBool firstWarning = PR_TRUE;
-
-        if(firstWarning) {
-            // Warn that MOZILLA_FIVE_HOME not set, once.
-            printf("Warning: MOZILLA_FIVE_HOME not set.\n");
-            firstWarning = PR_FALSE;
-        }
-#endif /* DEBUG */
-
-        // Fall back to current directory.
-        if (getcwd(buf, sizeof(buf)))
-        {
+        if (realpath(moz5, buf)) {
             localFile->InitWithNativePath(nsDependentCString(buf));
             *aFile = localFile;
             return NS_OK;
         }
     }
+#if defined(DEBUG)
+    static PRBool firstWarning = PR_TRUE;
+
+    if(!moz5 && firstWarning) {
+        // Warn that MOZILLA_FIVE_HOME not set, once.
+        printf("Warning: MOZILLA_FIVE_HOME not set.\n");
+        firstWarning = PR_FALSE;
+    }
+#endif /* DEBUG */
+
+    // Fall back to current directory.
+    if (getcwd(buf, sizeof(buf)))
+    {
+        localFile->InitWithNativePath(nsDependentCString(buf));
+        *aFile = localFile;
+        return NS_OK;
+    }
 
 #elif defined(XP_OS2)
     PPIB ppib;
diff --git a/mozilla/xpcom/io/nsLocalFileUnix.cpp b/mozilla/xpcom/io/nsLocalFileUnix.cpp
index 281113e8292..de6a41b4c4c 100644
--- a/mozilla/xpcom/io/nsLocalFileUnix.cpp
+++ b/mozilla/xpcom/io/nsLocalFileUnix.cpp
@@ -270,6 +270,9 @@ nsLocalFile::InitWithNativePath(const nsACString &filePath)
         }
         
         mPath = homePath + Substring(filePath, 1, filePath.Length() - 1);
+    } else if (filePath.IsEmpty() || filePath.First() != '/') {
+      NS_ERROR("Relative paths not allowed");
+      return NS_ERROR_FILE_UNRECOGNIZED_PATH;
     } else {
         mPath = filePath;
     }