combo-layer: exclude files

index 5f10e83..fb3fb50 100755
@@ -149,23 +149,27 @@ class Configuration(object):
             logger.error("ERROR: patchutils package is missing, please install it (e.g. # apt-get install patchutils)")
             sys.exit(1)
 
-def runcmd(cmd,destdir=None,printerr=True):
+def runcmd(cmd,destdir=None,printerr=True,out=None):
     """
         execute command, raise CalledProcessError if fail
         return output if succeed
     """
     logger.debug("run cmd '%s' in %s" % (cmd, os.getcwd() if destdir is None else destdir))
-    out = os.tmpfile()
+    if not out:
+        out = os.tmpfile()
+        err = out
+    else:
+        err = os.tmpfile()
     try:
-        subprocess.check_call(cmd, stdout=out, stderr=out, cwd=destdir, shell=True)
+        subprocess.check_call(cmd, stdout=out, stderr=err, cwd=destdir, shell=isinstance(cmd, str))
     except subprocess.CalledProcessError,e:
-        out.seek(0)
+        err.seek(0)
         if printerr:
-            logger.error("%s" % out.read())
+            logger.error("%s" % err.read())
         raise e
 
-    out.seek(0)
-    output = out.read()
+    err.seek(0)
+    output = err.read()
     logger.debug("output: %s" % output )
     return output
 

index fb3fb50..b121c99 100755
@@ -20,6 +20,7 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+import fnmatch
 import os, sys
 import optparse
 import logging

@@ -208,7 +209,18 @@ def action_init(conf, args):
             else:
                 extract_dir = os.getcwd()
             file_filter = repo.get('file_filter', "")
-            runcmd("git archive %s | tar -x -C %s %s" % (initialrev, extract_dir, file_filter), ldir)
+            files = runcmd("git archive %s | tar -x -v -C %s %s" % (initialrev, extract_dir, file_filter), ldir)
+            exclude_patterns = repo.get('file_exclude', '').split()
+            if exclude_patterns:
+                # Implement file removal by letting tar create the
+                # file and then deleting it in the file system
+                # again. Uses the list of files created by tar (easier
+                # than walking the tree).
+                for file in files.split('\n'):
+                    for pattern in exclude_patterns:
+                        if fnmatch.fnmatch(file, pattern):
+                            os.unlink(os.path.join(extract_dir, file))
+                            break
             if not lastrev:
                 lastrev = runcmd("git rev-parse %s" % initialrev, ldir).strip()
                 conf.update(name, "last_revision", lastrev, initmode=True)

@@ -423,6 +435,33 @@ def action_update(conf, args):
                 runcmd("%s %s %s %s" % (repo['hook'], patch, revlist[count], name))
                 count=count-1
 
+        # Step 3a: Filter out unwanted files and patches.
+        exclude = repo.get('file_exclude', '')
+        if exclude:
+            filter = ['filterdiff', '-p1']
+            for path in exclude.split():
+                filter.append('-x')
+                filter.append(path)
+            for patch in patchlist[:]:
+                filtered = patch + '.tmp'
+                with open(filtered, 'w') as f:
+                    runcmd(filter + [patch], out=f)
+                # Now check for empty patches.
+                if runcmd(['filterdiff', '--list', filtered]):
+                    # Possibly modified.
+                    os.unlink(patch)
+                    os.rename(filtered, patch)
+                else:
+                    # Empty, ignore it. Must also remove from revlist.
+                    fromline = open(patch, 'r').readline()
+                    m = re.match(r'''^From ([0-9a-fA-F]+) .*\n''', fromline)
+                    rev = m.group(1)
+                    logger.debug('skipping empty patch %s = %s' % (patch, rev))
+                    os.unlink(patch)
+                    os.unlink(filtered)
+                    patchlist.remove(patch)
+                    revlist.remove(rev)
+
         # Step 4: write patch list and revision list to file, for user to edit later
         patchlist_file = os.path.join(os.getcwd(), patch_dir, "patchlist-%s" % name)
         repo['patchlist'] = patchlist_file

index 8ad8615..0ef80cb 100644
@@ -38,6 +38,20 @@ last_revision =
 #   file_filter = src/*.c : only include the src *.c file
 #   file_filter = src/main.c src/Makefile.am : only include these two files
 
+# file_exclude: filter out these file(s)
+# file_exclude = [path] [path] ...
+#
+# Each entry must match a file name. In contrast do file_filter, matching
+# a directory has no effect. To achieve that, use append a * wildcard
+# at the end.
+#
+# Wildcards are applied to the complete path and also match slashes.
+#
+# example:
+#   file_exclude = src/foobar/*  : exclude everything under src/foobar
+#   file_exclude = src/main.c : filter out main.c after including it with file_filter = src/*.c
+#   file_exclude = *~ : exclude backup files
+
 # hook: if provided, the tool will call the hook to process the generated
 #     patch from upstream, and then apply the modified patch to the combo
 #     repo.