fix and optimize cached header handling in test runner

1 files changed, 2 insertions, 2 deletions

diff --git a/emscripten.py b/emscripten.py
index f7d1c9cc..7c3e3daf 100755
--- a/emscripten.py
+++ b/emscripten.py
@@ -232,12 +232,12 @@ def main(args):
         defines[key] = str(value)
       else:
         del defines[key]
-    settings['C_DEFINES'] = defines
+    #print >> sys.stderr, 'new defs:', str(defines).replace(',', ',\n  '), '\n\n'
+    settings.setdefault('C_DEFINES', {}).update(defines)
 
   # Compile the assembly to Javascript.
   emscript(args.infile, json.dumps(settings), args.outfile)
 
-
 if __name__ == '__main__':
   parser = optparse.OptionParser(
       usage='usage: %prog [-h] [-O] [-m] [-H HEADERS] [-o OUTFILE] [-s FOO=BAR]* infile',