Add external API to access detailed commit attributes

The following new external methods have been added:

GIT_EXTERN(const char *) git_commit_message_short(git_commit *commit);
GIT_EXTERN(const char *) git_commit_message(git_commit *commit);
GIT_EXTERN(time_t) git_commit_time(git_commit *commit);
GIT_EXTERN(const git_commit_person *) git_commit_committer(git_commit *commit);
GIT_EXTERN(const git_commit_person *) git_commit_author(git_commit *commit);
GIT_EXTERN(const git_tree *) git_commit_tree(git_commit *commit);

A new structure, git_commit_person has been added to represent a
commit's author or committer.

The parsing of a commit has been split in two phases.
When adding a commit to the revision pool:
	- the commit's ODB object is opened
	- its raw contents are parsed for commit TIME, PARENTS and TREE
		(the minimal amount of data required to traverse the pool)
	- the commit's ODB object is closed

When querying for extended information on a commit:
	- the commit's ODB object is reopened
	- its raw contents are parsed for the requested information
	- the commit's ODB object remains open to handle additional queries

New unit tests have been added for the new functionality:

	In t0401-parse: parse_person_test
	In t0402-details: query_details_test

Signed-off-by: Vicent Marti <tanoku@gmail.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/src/revwalk.c b/src/revwalk.c
index 422ef9df8..d4627ae2e 100644
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -92,8 +92,9 @@ int gitrp_push(git_revpool *pool, git_commit *commit)
 	if (commit->object.pool != pool || pool->walking)
 		return GIT_ERROR;
 
-	if (!commit->parsed) {
-		int error = git_commit_parse_existing(commit);
+	if (!commit->basic_parse) {
+		int error = git_commit__parse_basic(commit);
+
 		if (error < 0)
 			return error;
 	}
@@ -129,8 +130,8 @@ int gitrp__enroot(git_revpool *pool, git_commit *commit)
 	if (commit->seen)
 		return 0;
 
-	if (commit->parsed == 0) {
-		error = git_commit_parse_existing(commit);
+	if (!commit->basic_parse) {
+		error = git_commit__parse_basic(commit);
 		if (error < 0)
 			return error;
 	}