Merge ~nacc/git-ubuntu:use-dpkg-mergechangelogs into git-ubuntu:master

[Nish Aravamudan]

[Robie Basak (racb)]

Comments inline.

review: Needs Fixing

[Nish Aravamudan (nacc)]

I think I addressed all the review comments.

e537604... by Nish Aravamudan on 2017-07-27

gitubuntu/git_repository: cat-file produces extra blank lines

[Nish Aravamudan (nacc)]

Hi Robie, I just pushed one additional commit, which I think resolves the issue we discussed on IRC during the sprint, when `git cat-file` emits an extra newline after the file contents.

[Robie Basak (racb)]

Looks good!

I'm not keen on the clobbering of the work tree, but I think we need to fix that separately.

> gitubuntu/git_repository: cat-file produces extra blank lines

I think the commit summary should be written in the sense of what is being changed, rather than the problem being fixed. Though the problem being fixed is fine to explain the commit description.

So how about: "GitUbuntuRepository: suppress extra cat-file blank lines"

review: Approve

diff --git a/gitubuntu/git_repository.py b/gitubuntu/git_repository.py
index da330ab..ba0480b 100644
--- a/gitubuntu/git_repository.py
+++ b/gitubuntu/git_repository.py
@@ -439,7 +439,7 @@ class GitUbuntuRepository:
         cat_changelog_cmd = (
             "echo %s | "
             "git cat-file --batch --follow-symlinks | "
-            "sed -n '1{/^[^ ]* blob/!{p;q1}};2,$p'"
+            "sed -n '1{/^[^ ]* blob/!{p;q1}};${/^$/d};2,$p'"
             % changelog_file
         )
 
diff --git a/gitubuntu/lint.py b/gitubuntu/lint.py
index d1b2802..ef3652f 100644
--- a/gitubuntu/lint.py
+++ b/gitubuntu/lint.py
@@ -269,25 +269,31 @@ class GitUbuntuLint:
             self.local_repo.get_commitish(new).id)
         )
         self.local_repo.checkout_commitish(new)
+        changelog_files = []
         try:
-            for cmd in ['git-ubuntu.merge-changelogs', 'git-merge-changelogs']:
-                try:
-                    run([cmd, merge_base_id, old, new])
-                    break
-                except (CalledProcessError, FileNotFoundError):
-                    continue
-            else:
-                logging.error("Unable to find/execute merge-changelogs")
-                return None
-
+            for tree in [merge_base_id, old, new]:
+                changelog_files.append(
+                    self.local_repo.extract_file_from_treeish(
+                        tree,
+                        "debian/changelog",
+                    )
+                )
+            run(["dpkg-mergechangelogs"] + [f.name for f in changelog_files] +
+                ["debian/changelog"]
+            )
             self.local_repo.git_run(
-                ["--work-tree", ".", "add", "-f", "-A"],
+                ["--work-tree", ".", "add", "-f", "debian/changelog"],
             )
             cp = self.local_repo.git_run(
                 ["--work-tree", ".", "write-tree"],
             )
             return decode_binary(cp.stdout).strip()
+        except (CalledProcessError, FileNotFoundError):
+            logging.error("Unable to find/execute dpkg-mergechangelogs")
+            return None
         finally:
+            for f in changelog_files:
+                f.close()
             self.local_repo.git_run(["clean", "-f", "-d"])
             self.local_repo.reset_commitish(new)
             self.local_repo.checkout_commitish(commitish_id)