Implement partial reroll

It has been a common request to support partial series rerolls where
someone sends an amended patch as a follow-up to a previous series,
e.g.:

[PATCH v3 1/3] Patch one
[PATCH v3 2/3] Patch two
\- Re: [PATCH v3 2/3] Patch two
   Looks good, but please fix this $small_thing

   \- [PATCH v4 2/3] Patch two
[PATCH v3] Patch three

Previously, b4 refused to consider v4 as a complete new series, but now
it will properly perform a partial reroll, but only in the cases where
such patches are sent as follow-ups to the exact same patch number in
the previous series:

[PATCH v3->v4 1/3] Patch one
[PATCH     v4 2/3] Patch two
[PATCH v3->v4 3/3] Patch three

Reported-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Link: https://lore.kernel.org/r/CAPcyv4ggbuHbqKV33_TpE7pqxvRag34baJrX3yQe-jXOikoATQ@mail.gmail.com

1 files changed, 7 insertions, 1 deletions

diff --git a/b4/diff.py b/b4/diff.py
index 10f3159..38d2a9a 100644
--- a/b4/diff.py
+++ b/b4/diff.py
@@ -66,7 +66,7 @@ def diff_same_thread_series(cmdargs):
         lower = min(wantvers)
     else:
         upper = max(lmbx.series.keys())
-        lower = min(lmbx.series.keys())
+        lower = upper - 1
 
     if upper == lower:
         logger.critical('ERROR: Could not auto-find previous revision')
@@ -80,9 +80,15 @@ def diff_same_thread_series(cmdargs):
         return None, None
 
     if not lmbx.series[lower].complete:
+        lmbx.partial_reroll(lower, sloppytrailers=False, backfill=True)
+
+    if not lmbx.series[lower].complete:
         lmbx.backfill(lower)
 
     if not lmbx.series[upper].complete:
+        lmbx.partial_reroll(upper, sloppytrailers=False, backfill=True)
+
+    if not lmbx.series[upper].complete:
         lmbx.backfill(upper)
 
     return lmbx.series[lower], lmbx.series[upper]