Correct makelsr handling of local update (issue 6416045)

[PhilEHolmes]

Reviewers: ,

Message:
A small patch to fix makelsr's handling of local updates.  Don't want to
wait for countdown, but a review by those who understand this would be
helpful.

Description:
I omitted to specify properly what makelsr should do when it's doing a
"local" update - i.e. with no tarball specified.  In this case it should
only update snippets/new into snippets.  This patch fixes that.

Please review this at http://codereview.appspot.com/6416045/

Affected files:
  M scripts/auxiliar/makelsr.py


Index: scripts/auxiliar/makelsr.py
diff --git a/scripts/auxiliar/makelsr.py b/scripts/auxiliar/makelsr.py
index  
278173f6361b288b8d7ac30e753884e3734fee4d..099418b86f7534204ad10a2a216c70def82a5ceb  
100755
--- a/scripts/auxiliar/makelsr.py
+++ b/scripts/auxiliar/makelsr.py
@@ -149,6 +149,7 @@ def exit_with_usage (n=0):
     options_parser.print_help (sys.stderr)
     sys.exit (n)

+tags=[]
 if len (args):
     in_dir = args[0]
     if not (os.path.isdir (in_dir)):
@@ -156,6 +157,7 @@ if len (args):
         sys.exit (4)
     if len (args) > 1:
         exit_with_usage (2)
+    tags = os.listdir (in_dir)
 else:
     in_dir = '.'

@@ -175,8 +177,6 @@ if not os.path.exists (lilypond_bin):
     lilypond_bin = "lilypond"
 sys.stderr.write ("Using %s, %s\n" % (convert_ly, lilypond_bin))

-tags = os.listdir (in_dir)
-
 unsafe = []
 unconverted = []
 notags_files = []
@@ -305,9 +305,13 @@ def dump_file_list (file, file_list, update=False):
     f = open (file, 'w')
     f.write ('\n'.join (sorted (new_list)) + '\n')

-## clean out existing lys and generated files
-map (os.remove, glob.glob (os.path.join (lys_from_lsr, '*.ly')) +
-     glob.glob (os.path.join (lys_from_lsr, '*.snippet-list')))
+## clean out existing lys and generated files - but only when we're
+## completely recreating them from the tarball.  Otherwise
+## tags will be empty and so we can use this to skip this step
+
+if len(args) > 0:
+    map (os.remove, glob.glob (os.path.join (lys_from_lsr, '*.ly')) +
+        glob.glob (os.path.join (lys_from_lsr, '*.snippet-list')))

 # read LSR source where tags are defined by subdirs
 snippets, tag_lists = read_source_with_dirs (in_dir)