pick-ui: show commit date

With our ff-only merge setup, the commit date ends up being when the
commit actually landed (as opposed to when it was first written).

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Dylan Baker <dylan@pnwbakers.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/12289>
(cherry picked from commit 4128acdee3)

.pick_status.json

@@ -247,7 +247,7 @@
         "description": "pick-ui: show commit date",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null
     },

bin/pick/core.py

@@ -138,6 +138,14 @@ class Commit:
             c.resolution = Resolution(data['resolution'])
         return c
 
+    def date(self) -> str:
+        # Show commit date, ie. when the commit actually landed
+        # (as opposed to when it was first written)
+        return subprocess.check_output(
+            ['git', 'show', '--no-patch', '--format=%cs', self.sha],
+            stderr=subprocess.DEVNULL
+        ).decode("ascii").strip()
+
     async def apply(self, ui: 'UI') -> typing.Tuple[bool, str]:
         # FIXME: This isn't really enough if we fail to cherry-pick because the
         # git tree will still be dirty

bin/pick/ui.py

@@ -67,7 +67,7 @@ class CommitWidget(urwid.Text):
 
     def __init__(self, ui: 'UI', commit: 'core.Commit'):
         reason = commit.nomination_type.name.ljust(6)
-        super().__init__(f'{reason} {commit.sha[:10]} {commit.description}')
+        super().__init__(f'{commit.date()} {reason} {commit.sha[:10]} {commit.description}')
         self.ui = ui
         self.commit = commit