remove trivial whitespace

emcc

@@ -75,7 +75,7 @@ emcc can be influenced by a few environment variables:
   EMMAKEN_COMPILER - The compiler to be used, if you don't want the default clang.
 '''
 
-import os, sys, shutil, tempfile, subprocess, shlex, time
+import os, sys, shutil, tempfile, subprocess, shlex, time, re
 from subprocess import PIPE, STDOUT
 from tools import shared
 from tools.shared import Compression, execute, suffix, unsuffixed, unsuffixed_basename
@@ -1361,6 +1361,12 @@ try:
 
   flush_js_optimizer_queue()
 
+  if not minify_whitespace:
+    # Remove some trivial whitespace
+    src = open(final).read()
+    src = re.sub(r'\n+[ \n]*\n+', '\n', src)
+    open(final, 'w').write(src)
+
   # If we were asked to also generate HTML, do that
   if final_suffix == 'html':
     if DEBUG: print >> sys.stderr, 'emcc: generating HTML'