Merge branch 'nd/shallow-deepen'

The existing "git fetch --depth=<n>" option was hard to use
correctly when making the history of an existing shallow clone
deeper.  A new option, "--deepen=<n>", has been added to make this
easier to use.  "git clone" also learned "--shallow-since=<date>"
and "--shallow-exclude=<tag>" options to make it easier to specify
"I am interested only in the recent N months worth of history" and
"Give me only the history since that version".

* nd/shallow-deepen: (27 commits)
  fetch, upload-pack: --deepen=N extends shallow boundary by N commits
  upload-pack: add get_reachable_list()
  upload-pack: split check_unreachable() in two, prep for get_reachable_list()
  t5500, t5539: tests for shallow depth excluding a ref
  clone: define shallow clone boundary with --shallow-exclude
  fetch: define shallow boundary with --shallow-exclude
  upload-pack: support define shallow boundary by excluding revisions
  refs: add expand_ref()
  t5500, t5539: tests for shallow depth since a specific date
  clone: define shallow clone boundary based on time with --shallow-since
  fetch: define shallow boundary with --shallow-since
  upload-pack: add deepen-since to cut shallow repos based on time
  shallow.c: implement a generic shallow boundary finder based on rev-list
  fetch-pack: use a separate flag for fetch in deepening mode
  fetch-pack.c: mark strings for translating
  fetch-pack: use a common function for verbose printing
  fetch-pack: use skip_prefix() instead of starts_with()
  upload-pack: move rev-list code out of check_non_tip()
  upload-pack: make check_non_tip() clean things up on error
  upload-pack: tighten number parsing at "deepen" lines
  ...

1 files changed, 78 insertions, 0 deletions

diff --git a/shallow.c b/shallow.c
index 54e2db7334..2531e3af3b 100644
--- a/shallow.c
+++ b/shallow.c
@@ -10,6 +10,8 @@
 #include "diff.h"
 #include "revision.h"
 #include "commit-slab.h"
+#include "revision.h"
+#include "list-objects.h"
 
 static int is_shallow = -1;
 static struct stat_validity shallow_stat;
@@ -137,6 +139,82 @@ struct commit_list *get_shallow_commits(struct object_array *heads, int depth,
 	return result;
 }
 
+static void show_commit(struct commit *commit, void *data)
+{
+	commit_list_insert(commit, data);
+}
+
+/*
+ * Given rev-list arguments, run rev-list. All reachable commits
+ * except border ones are marked with not_shallow_flag. Border commits
+ * are marked with shallow_flag. The list of border/shallow commits
+ * are also returned.
+ */
+struct commit_list *get_shallow_commits_by_rev_list(int ac, const char **av,
+						    int shallow_flag,
+						    int not_shallow_flag)
+{
+	struct commit_list *result = NULL, *p;
+	struct commit_list *not_shallow_list = NULL;
+	struct rev_info revs;
+	int both_flags = shallow_flag | not_shallow_flag;
+
+	/*
+	 * SHALLOW (excluded) and NOT_SHALLOW (included) should not be
+	 * set at this point. But better be safe than sorry.
+	 */
+	clear_object_flags(both_flags);
+
+	is_repository_shallow(); /* make sure shallows are read */
+
+	init_revisions(&revs, NULL);
+	save_commit_buffer = 0;
+	setup_revisions(ac, av, &revs, NULL);
+
+	if (prepare_revision_walk(&revs))
+		die("revision walk setup failed");
+	traverse_commit_list(&revs, show_commit, NULL, &not_shallow_list);
+
+	/* Mark all reachable commits as NOT_SHALLOW */
+	for (p = not_shallow_list; p; p = p->next)
+		p->item->object.flags |= not_shallow_flag;
+
+	/*
+	 * mark border commits SHALLOW + NOT_SHALLOW.
+	 * We cannot clear NOT_SHALLOW right now. Imagine border
+	 * commit A is processed first, then commit B, whose parent is
+	 * A, later. If NOT_SHALLOW on A is cleared at step 1, B
+	 * itself is considered border at step 2, which is incorrect.
+	 */
+	for (p = not_shallow_list; p; p = p->next) {
+		struct commit *c = p->item;
+		struct commit_list *parent;
+
+		if (parse_commit(c))
+			die("unable to parse commit %s",
+			    oid_to_hex(&c->object.oid));
+
+		for (parent = c->parents; parent; parent = parent->next)
+			if (!(parent->item->object.flags & not_shallow_flag)) {
+				c->object.flags |= shallow_flag;
+				commit_list_insert(c, &result);
+				break;
+			}
+	}
+	free_commit_list(not_shallow_list);
+
+	/*
+	 * Now we can clean up NOT_SHALLOW on border commits. Having
+	 * both flags set can confuse the caller.
+	 */
+	for (p = result; p; p = p->next) {
+		struct object *o = &p->item->object;
+		if ((o->flags & both_flags) == both_flags)
+			o->flags &= ~not_shallow_flag;
+	}
+	return result;
+}
+
 static void check_shallow_file_for_update(void)
 {
 	if (is_shallow == -1)