patman: Support collecting all lines in the commit message

In some cases we want to collect all lines in the commit message so that
the commit can be recreated with the same message as before, or perhaps
with light filtering.

Add support for this.

Series-to: u-boot
Cover-letter:
patman: Minor improvements to prepare for series handling
This series includes a number of internal improvements to patman:
- Tidy-up of parsing
- Adjust how tests create the git tree
- Support for creating patches in a different git directory
- Faster determination of the upstream branch
- Ability to collect the body of a commit message as a series of lines
END

Signed-off-by: Simon Glass <sjg@chromium.org>

tools/patman/patchstream.py

@@ -109,6 +109,8 @@ class PatchStream:
         self.recent_unquoted = queue.Queue()
         self.was_quoted = None
         self.insert_base_commit = insert_base_commit
+        self.lines = []                  # All lines in a commit message
+        self.msg = None                  # Full commit message including subject
 
     @staticmethod
     def process_text(text, is_comment=False):
@@ -190,11 +192,22 @@ class PatchStream:
         """
         self.commit.add_rtag(rtag_type, who)
 
-    def _close_commit(self):
-        """Save the current commit into our commit list, and reset our state"""
+    def _close_commit(self, skip_last_line):
+        """Save the current commit into our commit list, and reset our state
+
+        Args:
+            skip_last_line (bool): True to omit the final line of self.lines
+                when building the commit message. This is normally the blank
+                line between two commits, except at the end of the log, where
+                there is no blank line
+        """
         if self.commit and self.is_log:
+            # Skip the blank line before the subject
+            lines = self.lines[:-1] if skip_last_line else self.lines
+            self.commit.msg = '\n'.join(lines[1:]) + '\n'
             self.series.AddCommit(self.commit)
             self.commit = None
+            self.lines = []
         # If 'END' is missing in a 'Cover-letter' section, and that section
         # happens to show up at the very end of the commit message, this is
         # the chance for us to fix it up.
@@ -345,6 +358,8 @@ class PatchStream:
                 self.state += 1
         elif commit_match:
             self.state = STATE_MSG_HEADER
+        if self.state != STATE_MSG_HEADER:
+            self.lines.append(line)
 
         # If a tag is detected, or a new commit starts
         if series_tag_match or commit_tag_match or change_id_match or \
@@ -499,7 +514,7 @@ class PatchStream:
 
         # Detect the start of a new commit
         elif commit_match:
-            self._close_commit()
+            self._close_commit(True)
             self.commit = commit.Commit(commit_match.group(1))
 
         # Detect tags in the commit message
@@ -579,7 +594,7 @@ class PatchStream:
         """Close out processing of this patch stream"""
         self._finalise_snippet()
         self._finalise_change()
-        self._close_commit()
+        self._close_commit(False)
         if self.lines_after_test:
             self._add_warn('Found %d lines after TEST=' % self.lines_after_test)