am: properly handle non-git diffs

We were not properly parsing patches generated by something other than
"git diff" or "git format-patch". Notably, these are pretty rare, but we
still shouldn't fail when doing that.

This additionally adds a few tests and fixes a silly mistake that I had
all along in the sample data.

Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217852
Signed-off-by: Konstantin Ryabitsev <konstantin@linuxfoundation.org>

29 files changed, 196 insertions, 51 deletions

diff --git a/b4/__init__.py b/b4/__init__.py
index 14ef53d..e834af2 100644
--- a/b4/__init__.py
+++ b/b4/__init__.py
@@ -1752,8 +1752,12 @@ class LoreMessage:
         if len(basement):
             if not len(trailers):
                 body += '\n'
-            body += '---\n'
-            body += basement.rstrip('\r\n') + '\n'
+            if DIFFSTAT_RE.search(basement):
+                body += '---\n'
+            else:
+                # If we don't have a diffstat, then we don't need to add a ---
+                body += '\n'
+            body += basement.strip('\r\n') + '\n'
 
         if len(signature):
             body += '-- \n'
@@ -1787,6 +1791,12 @@ class LoreMessage:
             if len(parts) == 2:
                 parts[1] = 'diff ' + parts[1]
             basement = parts[1].rstrip('\n')
+        elif body.find('\n--- a/') >= 0:
+            # patches generated by some really peculiar tools
+            parts = body.split('\n--- a/', 1)
+            if len(parts) == 2:
+                parts[1] = '--- a/' + parts[1]
+            basement = parts[1].rstrip('\n')
 
         mbody = parts[0].strip('\n')
 
diff --git a/tests/samples/trailers-followup-custody-ref-ordered.txt b/tests/samples/trailers-followup-custody-ref-ordered.txt
index 6f76718..be4d2ee 100644
--- a/tests/samples/trailers-followup-custody-ref-ordered.txt
+++ b/tests/samples/trailers-followup-custody-ref-ordered.txt
@@ -21,12 +21,11 @@ Suggested-by: Friendly Suggester <suggested-by@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-custody-ref-unordered.txt b/tests/samples/trailers-followup-custody-ref-unordered.txt
index 5a44260..86b50e4 100644
--- a/tests/samples/trailers-followup-custody-ref-unordered.txt
+++ b/tests/samples/trailers-followup-custody-ref-unordered.txt
@@ -21,12 +21,11 @@ Cc: Dev Eloper1 <dev-eloper1@example.com>
 Cc: Dev Eloper2 <dev-eloper2@example.com>
 Cc: Some List <list-1@lists.example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-custody-ref-with-ignored.txt b/tests/samples/trailers-followup-custody-ref-with-ignored.txt
index c9d9cdf..11ccb7e 100644
--- a/tests/samples/trailers-followup-custody-ref-with-ignored.txt
+++ b/tests/samples/trailers-followup-custody-ref-with-ignored.txt
@@ -20,12 +20,11 @@ Cc: Dev Eloper1 <dev-eloper1@example.com>
 Cc: Dev Eloper2 <dev-eloper2@example.com>
 Cc: Some List <list-1@lists.example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-custody.mbox b/tests/samples/trailers-followup-custody.mbox
index 0c4e4b8..511c7a2 100644
--- a/tests/samples/trailers-followup-custody.mbox
+++ b/tests/samples/trailers-followup-custody.mbox
@@ -21,7 +21,7 @@ Signed-off-by: Test Override <test-override@example.com>
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-non-git-patch-ref-defaults.txt b/tests/samples/trailers-followup-non-git-patch-ref-defaults.txt
new file mode 100644
index 0000000..59d9b71
--- /dev/null
+++ b/tests/samples/trailers-followup-non-git-patch-ref-defaults.txt
@@ -0,0 +1,29 @@
+From git@z Thu Jan  1 00:00:00 1970
+Subject: [PATCH] Simple test
+From: Test Test <test@example.com>
+Date: Tue, 30 Aug 2022 11:19:07 -0400
+Message-Id: <orig-message@example.com>
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 7bit
+
+Follow-up trailer collating test.
+
+Fixes: abcdef01234567890
+Reviewed-by: Original Reviewer <original-reviewer@example.com>
+Link: https://msgid.link/some@msgid.here
+Signed-off-by: Original Submitter <original-submitter@example.com>
+Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
+
+--- a/b4/junk.py
++++ b/b4/junk.py
+@@@ -1,1 +1,1 @@ def junk():
+ 
+ 
+-junk1
++junk2
+ 
+ 
+-- 
+2.wong.fu
+
diff --git a/tests/samples/trailers-followup-non-git-patch.mbox b/tests/samples/trailers-followup-non-git-patch.mbox
new file mode 100644
index 0000000..3bc722a
--- /dev/null
+++ b/tests/samples/trailers-followup-non-git-patch.mbox
@@ -0,0 +1,42 @@
+From foo@z Thu Jan  1 00:00:00 1970
+From: Test Test <test@example.com>
+Subject: [PATCH] Simple test
+To: Some List <list-1@lists.example.com>
+Cc: Dev Eloper1 <dev-eloper1@example.com>,
+ Dev Eloper2 <dev-eloper2@example.com>
+Date: Tue, 30 Aug 2022 11:19:07 -0400
+Message-Id: <orig-message@example.com>
+
+Follow-up trailer collating test.
+
+Fixes: abcdef01234567890
+Reviewed-by: Original Reviewer <original-reviewer@example.com>
+Link: https://msgid.link/some@msgid.here
+Signed-off-by: Original Submitter <original-submitter@example.com>
+
+--- a/b4/junk.py
++++ b/b4/junk.py
+@@@ -1,1 +1,1 @@ def junk():
+ 
+ 
+-junk1
++junk2
+ 
+ 
+-- 
+2.wong.fu
+
+From foo@z Thu Jan  1 00:00:00 1970
+From: Followup Reviewer1 <followup-reviewer1@example.com>
+Subject: Re: [PATCH] Simple test
+Date: Tue, 30 Aug 2022 11:19:07 -0400
+Message-Id: <fwup-message-1@example.com>
+In-Reply-To: <orig-message@example.com>
+References: <orig-message@example.com>
+
+> This is a simple trailer parsing test.
+
+Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
+
+--
+My sig
diff --git a/tests/samples/trailers-followup-nore-ref-defaults.txt b/tests/samples/trailers-followup-nore-ref-defaults.txt
index 3794a89..9f78bd3 100644
--- a/tests/samples/trailers-followup-nore-ref-defaults.txt
+++ b/tests/samples/trailers-followup-nore-ref-defaults.txt
@@ -14,12 +14,11 @@ Reviewed-by: Original Reviewer <original-reviewer@example.com>
 Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-nore.mbox b/tests/samples/trailers-followup-nore.mbox
index 458d958..27dddd6 100644
--- a/tests/samples/trailers-followup-nore.mbox
+++ b/tests/samples/trailers-followup-nore.mbox
@@ -18,7 +18,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-partial-reroll-ref-defaults.txt b/tests/samples/trailers-followup-partial-reroll-ref-defaults.txt
index ec5d604..2656e54 100644
--- a/tests/samples/trailers-followup-partial-reroll-ref-defaults.txt
+++ b/tests/samples/trailers-followup-partial-reroll-ref-defaults.txt
@@ -14,12 +14,11 @@ Reviewed-by: Original Reviewer <original-reviewer@example.com>
 Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
@@ -47,12 +46,11 @@ Reviewed-by: Original Reviewer <original-reviewer@example.com>
 Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/bogus.py b/b4/bogus.py
 index 12345678..23456789 100644
 --- a/b4/bogus.py
---- b/b4/bogus.py
++++ b/b4/bogus.py
 @@@ -1,1 +1,1 @@ def bogus():
  
  
diff --git a/tests/samples/trailers-followup-partial-reroll.mbox b/tests/samples/trailers-followup-partial-reroll.mbox
index 0a5644f..1f78553 100644
--- a/tests/samples/trailers-followup-partial-reroll.mbox
+++ b/tests/samples/trailers-followup-partial-reroll.mbox
@@ -37,7 +37,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
@@ -70,7 +70,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/bupkes.py b/b4/bupkes.py
 index 12345678..23456789 100644
 --- a/b4/bupkes.py
---- b/b4/bupkes.py
++++ b/b4/bupkes.py
 @@@ -1,1 +1,1 @@ def bupkes():
  
  
@@ -134,7 +134,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/bogus.py b/b4/bogus.py
 index 12345678..23456789 100644
 --- a/b4/bogus.py
---- b/b4/bogus.py
++++ b/b4/bogus.py
 @@@ -1,1 +1,1 @@ def bogus():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-addlink.txt b/tests/samples/trailers-followup-single-ref-addlink.txt
index 07ec6cb..e0c4826 100644
--- a/tests/samples/trailers-followup-single-ref-addlink.txt
+++ b/tests/samples/trailers-followup-single-ref-addlink.txt
@@ -17,12 +17,11 @@ Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
 Link: https://lore.kernel.org/r/orig-message@example.com
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-addmsgid.txt b/tests/samples/trailers-followup-single-ref-addmsgid.txt
index fcdd79a..eeed03d 100644
--- a/tests/samples/trailers-followup-single-ref-addmsgid.txt
+++ b/tests/samples/trailers-followup-single-ref-addmsgid.txt
@@ -17,12 +17,11 @@ Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
 Message-Id: <orig-message@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-addmysob.txt b/tests/samples/trailers-followup-single-ref-addmysob.txt
index 497d62e..31032ba 100644
--- a/tests/samples/trailers-followup-single-ref-addmysob.txt
+++ b/tests/samples/trailers-followup-single-ref-addmysob.txt
@@ -16,12 +16,11 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-copyccs.txt b/tests/samples/trailers-followup-single-ref-copyccs.txt
index 86d1c97..6fc2d0a 100644
--- a/tests/samples/trailers-followup-single-ref-copyccs.txt
+++ b/tests/samples/trailers-followup-single-ref-copyccs.txt
@@ -19,12 +19,11 @@ Cc: Dev Eloper1 <dev-eloper1@example.com>
 Cc: Dev Eloper2 <dev-eloper2@example.com>
 Cc: Some List <list-1@lists.example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-defaults.txt b/tests/samples/trailers-followup-single-ref-defaults.txt
index 2d53ca7..d65ffce 100644
--- a/tests/samples/trailers-followup-single-ref-defaults.txt
+++ b/tests/samples/trailers-followup-single-ref-defaults.txt
@@ -15,12 +15,11 @@ Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-noadd.txt b/tests/samples/trailers-followup-single-ref-noadd.txt
index 6cab56c..cda0610 100644
--- a/tests/samples/trailers-followup-single-ref-noadd.txt
+++ b/tests/samples/trailers-followup-single-ref-noadd.txt
@@ -18,7 +18,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-ordered.txt b/tests/samples/trailers-followup-single-ref-ordered.txt
index 44b2b72..309be50 100644
--- a/tests/samples/trailers-followup-single-ref-ordered.txt
+++ b/tests/samples/trailers-followup-single-ref-ordered.txt
@@ -19,12 +19,11 @@ Cc: Some List <list-1@lists.example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single-ref-sloppy.txt b/tests/samples/trailers-followup-single-ref-sloppy.txt
index 137a6ce..4cb72dd 100644
--- a/tests/samples/trailers-followup-single-ref-sloppy.txt
+++ b/tests/samples/trailers-followup-single-ref-sloppy.txt
@@ -17,12 +17,11 @@ Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Tested-by: Followup Reviewer2 <followup-reviewer2@example.com>
 Reviewed-by: Mismatched Reviewer1 <mismatched-reviewer1@example.net>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-single.mbox b/tests/samples/trailers-followup-single.mbox
index b12f6ba..f3f788f 100644
--- a/tests/samples/trailers-followup-single.mbox
+++ b/tests/samples/trailers-followup-single.mbox
@@ -18,7 +18,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-followup-with-cover-ref-addlink.txt b/tests/samples/trailers-followup-with-cover-ref-addlink.txt
index d0091c6..8428a4a 100644
--- a/tests/samples/trailers-followup-with-cover-ref-addlink.txt
+++ b/tests/samples/trailers-followup-with-cover-ref-addlink.txt
@@ -15,12 +15,11 @@ Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Link: https://lore.kernel.org/r/patch-1-message@example.com
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
@@ -49,12 +48,11 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Link: https://lore.kernel.org/r/patch-2-message@example.com
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/bupkes.py b/b4/bupkes.py
 index 12345678..23456789 100644
 --- a/b4/bupkes.py
---- b/b4/bupkes.py
++++ b/b4/bupkes.py
 @@@ -1,1 +1,1 @@ def bupkes():
  
  
diff --git a/tests/samples/trailers-followup-with-cover-ref-covertrailers.txt b/tests/samples/trailers-followup-with-cover-ref-covertrailers.txt
index d182f70..5ef0d7a 100644
--- a/tests/samples/trailers-followup-with-cover-ref-covertrailers.txt
+++ b/tests/samples/trailers-followup-with-cover-ref-covertrailers.txt
@@ -15,12 +15,11 @@ Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Coverletter Reviewer1 <followup-reviewer1@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
@@ -49,12 +48,11 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Reviewed-by: Coverletter Reviewer1 <followup-reviewer1@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/bupkes.py b/b4/bupkes.py
 index 12345678..23456789 100644
 --- a/b4/bupkes.py
---- b/b4/bupkes.py
++++ b/b4/bupkes.py
 @@@ -1,1 +1,1 @@ def bupkes():
  
  
diff --git a/tests/samples/trailers-followup-with-cover-ref-defaults.txt b/tests/samples/trailers-followup-with-cover-ref-defaults.txt
index 86538a8..858d103 100644
--- a/tests/samples/trailers-followup-with-cover-ref-defaults.txt
+++ b/tests/samples/trailers-followup-with-cover-ref-defaults.txt
@@ -14,12 +14,11 @@ Reviewed-by: Original Reviewer <original-reviewer@example.com>
 Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
@@ -47,12 +46,11 @@ Link: https://msgid.link/some@msgid.here
 Signed-off-by: Original Submitter <original-submitter@example.com>
 Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
 Signed-off-by: Test Override <test-override@example.com>
----
 
 diff --git a/b4/bupkes.py b/b4/bupkes.py
 index 12345678..23456789 100644
 --- a/b4/bupkes.py
---- b/b4/bupkes.py
++++ b/b4/bupkes.py
 @@@ -1,1 +1,1 @@ def bupkes():
  
  
diff --git a/tests/samples/trailers-followup-with-cover.mbox b/tests/samples/trailers-followup-with-cover.mbox
index 52c14c4..f2c2c6d 100644
--- a/tests/samples/trailers-followup-with-cover.mbox
+++ b/tests/samples/trailers-followup-with-cover.mbox
@@ -37,7 +37,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
@@ -70,7 +70,7 @@ Signed-off-by: Original Submitter <original-submitter@example.com>
 diff --git a/b4/bupkes.py b/b4/bupkes.py
 index 12345678..23456789 100644
 --- a/b4/bupkes.py
---- b/b4/bupkes.py
++++ b/b4/bupkes.py
 @@@ -1,1 +1,1 @@ def bupkes():
  
  
diff --git a/tests/samples/trailers-followup-with-diffstat-ref-defaults.txt b/tests/samples/trailers-followup-with-diffstat-ref-defaults.txt
new file mode 100644
index 0000000..3555f6e
--- /dev/null
+++ b/tests/samples/trailers-followup-with-diffstat-ref-defaults.txt
@@ -0,0 +1,34 @@
+From git@z Thu Jan  1 00:00:00 1970
+Subject: [PATCH] Simple test
+From: Test Test <test@example.com>
+Date: Tue, 30 Aug 2022 11:19:07 -0400
+Message-Id: <orig-message@example.com>
+MIME-Version: 1.0
+Content-Type: text/plain; charset="utf-8"
+Content-Transfer-Encoding: 7bit
+
+Follow-up trailer collating test.
+
+Fixes: abcdef01234567890
+Reviewed-by: Original Reviewer <original-reviewer@example.com>
+Link: https://msgid.link/some@msgid.here
+Signed-off-by: Original Submitter <original-submitter@example.com>
+Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
+---
+ b4/junk.py | 1 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/b4/junk.py b/b4/junk.py
+index 12345678..23456789 100644
+--- a/b4/junk.py
++++ b/b4/junk.py
+@@@ -1,1 +1,1 @@ def junk():
+ 
+ 
+-junk1
++junk2
+ 
+ 
+-- 
+2.wong.fu
+
diff --git a/tests/samples/trailers-followup-with-diffstat.mbox b/tests/samples/trailers-followup-with-diffstat.mbox
new file mode 100644
index 0000000..f1c0d31
--- /dev/null
+++ b/tests/samples/trailers-followup-with-diffstat.mbox
@@ -0,0 +1,47 @@
+From foo@z Thu Jan  1 00:00:00 1970
+From: Test Test <test@example.com>
+Subject: [PATCH] Simple test
+To: Some List <list-1@lists.example.com>
+Cc: Dev Eloper1 <dev-eloper1@example.com>,
+ Dev Eloper2 <dev-eloper2@example.com>
+Date: Tue, 30 Aug 2022 11:19:07 -0400
+Message-Id: <orig-message@example.com>
+
+Follow-up trailer collating test.
+
+Fixes: abcdef01234567890
+Reviewed-by: Original Reviewer <original-reviewer@example.com>
+Link: https://msgid.link/some@msgid.here
+Signed-off-by: Original Submitter <original-submitter@example.com>
+---
+ b4/junk.py | 1 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/b4/junk.py b/b4/junk.py
+index 12345678..23456789 100644
+--- a/b4/junk.py
++++ b/b4/junk.py
+@@@ -1,1 +1,1 @@ def junk():
+ 
+ 
+-junk1
++junk2
+ 
+ 
+-- 
+2.wong.fu
+
+From foo@z Thu Jan  1 00:00:00 1970
+From: Followup Reviewer1 <followup-reviewer1@example.com>
+Subject: Re: [PATCH] Simple test
+Date: Tue, 30 Aug 2022 11:19:07 -0400
+Message-Id: <fwup-message-1@example.com>
+In-Reply-To: <orig-message@example.com>
+References: <orig-message@example.com>
+
+> This is a simple trailer parsing test.
+
+Reviewed-by: Followup Reviewer1 <followup-reviewer1@example.com>
+
+--
+My sig
diff --git a/tests/samples/trailers-test-extinfo.txt b/tests/samples/trailers-test-extinfo.txt
index d36abbb..aa61e8d 100644
--- a/tests/samples/trailers-test-extinfo.txt
+++ b/tests/samples/trailers-test-extinfo.txt
@@ -17,7 +17,7 @@ Signed-off-by: Wrapped Persontrailer
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/samples/trailers-test-simple.txt b/tests/samples/trailers-test-simple.txt
index 693d781..da64caf 100644
--- a/tests/samples/trailers-test-simple.txt
+++ b/tests/samples/trailers-test-simple.txt
@@ -12,7 +12,7 @@ Link: https://msgid.link/some@msgid.here
 diff --git a/b4/junk.py b/b4/junk.py
 index 12345678..23456789 100644
 --- a/b4/junk.py
---- b/b4/junk.py
++++ b/b4/junk.py
 @@@ -1,1 +1,1 @@ def junk():
  
  
diff --git a/tests/test___init__.py b/tests/test___init__.py
index a38cd32..223b61e 100644
--- a/tests/test___init__.py
+++ b/tests/test___init__.py
@@ -101,6 +101,8 @@ def test_parse_trailers(sampledir, source, expected):
      {'trailers-ignore-from': 'followup-reviewer1@example.com'}),
     ('partial-reroll', {}, {'addmysob': True}, 'defaults', {}),
     ('nore', {}, {}, 'defaults', {}),
+    ('non-git-patch', {}, {}, 'defaults', {}),
+    ('with-diffstat', {}, {}, 'defaults', {}),
 ])
 def test_followup_trailers(sampledir, source, serargs, amargs, reference, b4cfg):
     b4.MAIN_CONFIG.update(b4cfg)