Merge pull request #38804 from alexbleotu/root_dir_fix-2016.3-gh

Second attempt to fix prepending of root_dir to paths

salt/config/__init__.py

@@ -1753,11 +1753,22 @@ def prepend_root_dir(opts, path_options):
     '''
     root_dir = os.path.abspath(opts['root_dir'])
     root_opt = opts['root_dir'].rstrip(os.sep)
+    def_root_dir = salt.syspaths.ROOT_DIR.rstrip(os.sep)
     for path_option in path_options:
         if path_option in opts:
             path = opts[path_option]
-            if path == root_opt or path.startswith(root_opt + os.sep):
+            # When running testsuite, salt.syspaths.ROOT_DIR is often empty
+            if def_root_dir != '' and (path == def_root_dir or path.startswith(def_root_dir + os.sep)):
+                # Remove the default root dir so we can add the override
+                path = path[len(def_root_dir):]
+            elif path == root_opt or path.startswith(root_opt + os.sep):
+                # Remove relative root dir so we can add the absolute root dir
                 path = path[len(root_opt):]
+            elif os.path.isabs(path_option):
+                # Absolute path (not default or overriden root_dir)
+                # No prepending required
+                continue
+            # Prepending the root dir
             opts[path_option] = salt.utils.path_join(root_dir, path)