MAPPING.CONFIG not found when calling genattrib.py from a different directory

[JonoYang]

Similar to #267, genattrib.py does not look for MAPPING.CONFIG in the same directory as genattrib.py. A similar fix is needed.

[pombredanne]

This ticket was closed but this commit was never cherry picked c87c1ff nor merged in the v2-maintainance branch.... not sure this is an issue or not

[pombredanne]

For reference this is the uncommitted patch:

From c87c1ff66a281462f8bba82cf4c1a135f44f1108 Mon Sep 17 00:00:00 2001
From: Jono Yang <jyang@nexb.com>
Date: Thu, 22 Dec 2016 14:41:29 -0800
Subject: [PATCH] #270 Look for MAPPING.CONFIG in the same directory as
 genattrib.py by prepending the absolute path to the directory genattrib.py is
 to 'MAPPING.CONFIG'

---
 about_code_tool/genattrib.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/about_code_tool/genattrib.py b/about_code_tool/genattrib.py
index bb3edeb..f5da7ce 100644
--- a/about_code_tool/genattrib.py
+++ b/about_code_tool/genattrib.py
@@ -15,7 +15,7 @@
 # ============================================================================
 
 """
-Tool to generate component attribution based on a set of .ABOUTfiles. 
+Tool to generate component attribution based on a set of .ABOUTfiles.
 
 Optionally accepts a list (i.e. a subset) of ABOUT file paths to limit the
 generated attribution to this subset.
@@ -145,9 +145,9 @@ def main(parser, options, args):
     elif verbosity >= 2:
         handler.setLevel(logging.WARNING)
 
-    if mapping_config:
-        if not exists('MAPPING.CONFIG'):
-            print("ERROR: The 'MAPPING.CONFIG' file does not exist.")
+    mapping_config_path = os.path.join(os.path.dirname(os.path.realpath(__file__)), 'MAPPING.CONFIG')
+    if mapping_config and not exists(mapping_config_path):
+            print("ERROR: The file 'MAPPING.CONFIG' does not exist.")
             sys.exit(errno.EINVAL)
 
     if template_location: