Adds clean room patch development, and patch cleanliness verification

2 files changed, 44 insertions, 13 deletions

diff --git a/modules/packagesource.py b/modules/packagesource.py
index d70ddd9..d556ef5 100644
--- a/modules/packagesource.py
+++ b/modules/packagesource.py
@@ -78,4 +78,4 @@ class PackageSource(Directory):
         raise NotImplementedError
 
     def branch_dir(self, *args):
-        return join(self.branches_dir, self.branch(*args))
+        return join(self.dir, self.branch(*args))
diff --git a/modules/sourceball.py b/modules/sourceball.py
index 3a38c01..8d102a8 100644
--- a/modules/sourceball.py
+++ b/modules/sourceball.py
@@ -19,6 +19,7 @@ from __future__ import with_statement
 
 import tarfile
 
+from contextlib import contextmanager
 from os import makedirs, getcwd, listdir
 from os.path import abspath, split, basename, join
 from shutil import copytree
@@ -101,21 +102,40 @@ class SourceBall(PackageSource):
             next = '0' + next
         return next
 
+    @contextmanager
+    def do_diff(self, src, tgt):
+        cmd = ['diff', '-r', '-u', '-X', DIFF_EXCLUDES_FILE,
+               src, tgt]
+        with pwd(self.pkg_src_dir):
+            with log_file('diff.log') as diff_out:
+                def command(fd):
+                    p = Popen(cmd, stdout=fd, stderr=diff_out)
+                    log.info('generating patch %s, please wait...'
+                             % fd.name)
+                    p.communicate()
+                yield command
+        
     def generate_patch(self, patch_name):
         prefix = self.next_patch_num + '.'
         patch_name = patch_name + '.patch' if not patch_name.endswith('.patch') else patch_name
         patch_name = prefix + patch_name
         log.debug('patch_name ' + patch_name)
-        cmd = ['diff', '-r', '-u', '-X', DIFF_EXCLUDES_FILE,
-               self.branch('orig'), '.']
-        with pwd(self.pkg_src_dir):
-            with log_file('diff.log') as diff_out:
-                with file(patch_name, 'w') as patch_file:
-                    with pwd(self.dir):
-                        p = Popen(cmd, stdout=patch_file, stderr=diff_out)
-                        log.info('generating patch %s, please wait...'
-                                 % patch_name)
-                        p.communicate()
+        with self.patches_applied('orig'):
+            with self.do_diff(self.branch('orig'), '.') as diff:
+                with pwd(self.dir):
+                    with file(join(self.pkg_src_dir, patch_name), 'w') as patch_file:
+                        diff(patch_file)
+            # We have to do this last step because of the context manager
+            # it assumes that this last patch has also been applied
+            patch_name = join(self.pkg_src_dir, patch_name)
+            with pwd(self.branch_dir('orig')):
+                self.apply_patch(patch_name)
+
+    @contextmanager
+    def patches_applied(self, *args):
+        self.apply_patches(*args)
+        yield
+        self.remove_patches(*args)
 
     def setup_sourceball(self, ver=''):
         return
@@ -153,12 +173,12 @@ class SourceBall(PackageSource):
         self.do_patch(patch, ['patch', '-p0', '-R'])
 
     def apply_patches(self, *args):
-        with pwd(self.branch('orig')):
+        with pwd(self.branch(*args)):
             for patch in sorted(self.patches):
                 self.apply_patch(patch)
 
     def remove_patches(self, *args):
-        with pwd(self.branch('orig')):
+        with pwd(self.branch(*args)):
             for patch in list(reversed(self.patches)):
                 self.remove_patch(patch)
 
@@ -170,5 +190,16 @@ class SourceBall(PackageSource):
             self.do_patch(patch_file, cmd)
         patch_name = basename(patch_file)
         self.generate_patch(patch_name)
+    
+    def verify_patches(self, *args):
+        test_file = join(self.pkg_src_dir, 'test.patch.')
+        with self.patches_applied(*args):
+            with self.do_diff(self.branch('orig'), '.') as diff:
+                with pwd(self.dir):
+                    with file(test_file, 'w') as patch_file:
+                        diff(patch_file)
+        clean = False if len(file(test_file).read()) else True
+        log.info('Verified clean patches: ' + str(clean))
+        return clean
 
 __all__ = ['SourceBall']