This refactor is motivated by a desire to add a "dry_run" parameter to
create_branch() that will validate whether or not a branch can be
created without actually creating it - this behavior will be used in a
subsequent commit that adds `git branch --recurse-submodules topic`.
Adding "dry_run" is not obvious because create_branch() is also used to
set tracking information without creating a branch, i.e. when using
--set-upstream-to. This appears to be a leftover from 4fc5006676 (Add
branch --set-upstream, 2010-01-18), when --set-upstream would sometimes
create a branch and sometimes update tracking information without
creating a branch. However, we no longer support --set-upstream, so it
makes more sense to set tracking information with another function and
use create_branch() only to create branches. In a later commit, we will
remove the now-unnecessary logic from create_branch() so that "dry_run"
becomes trivial to implement.
Introduce dwim_and_setup_tracking(), which replaces create_branch()
in `git branch --set-upstream-to`. Ensure correctness by moving the DWIM
and branch validation logic from create_branch() into a helper function,
dwim_branch_start(), so that the logic is shared by both functions.
Signed-off-by: Glen Choo <chooglen@xxxxxxxxxx>
---
branch.c | 87 ++++++++++++++++++++++++++++++++++++------------
branch.h | 22 ++++++++++++
builtin/branch.c | 9 ++---
3 files changed, 91 insertions(+), 27 deletions(-)
diff --git a/branch.c b/branch.c
index eed8665b76..54e989f3c8 100644
--- a/branch.c
+++ b/branch.c
@@ -212,9 +212,11 @@ static int inherit_tracking(struct tracking *tracking, const char *orig_ref)
}
/*
- * This is called when new_ref is branched off of orig_ref, and tries
- * to infer the settings for branch.<new_ref>.{remote,merge} from the
- * config.
+ * Used internally to set the branch.<new_ref>.{remote,merge} config
+ * settings so that branch 'new_ref' tracks 'orig_ref'. Unlike
+ * dwim_and_setup_tracking(), this does not do DWIM, i.e. "origin/main"
+ * will not be expanded to "refs/remotes/origin/main", so it is not safe
+ * for 'orig_ref' to be raw user input.
*/
static void setup_tracking(const char *new_ref, const char *orig_ref,
enum branch_track track, int quiet)
@@ -239,7 +241,7 @@ static void setup_tracking(const char *new_ref, const char *orig_ref,
case BRANCH_TRACK_INHERIT:
break;
default:
- return;
+ goto cleanup;
}
if (tracking.matches > 1)
@@ -252,6 +254,7 @@ static void setup_tracking(const char *new_ref, const char *orig_ref,
tracking.srcs) < 0)
exit(-1);
+cleanup:
string_list_clear(tracking.srcs, 0);
}
@@ -340,31 +343,37 @@ N_("\n"
"will track its remote counterpart, you may want to use\n"
"\"git push -u\" to set the upstream config as you push.");
-void create_branch(struct repository *r,
- const char *name, const char *start_name,
- int force, int clobber_head_ok, int reflog,
- int quiet, enum branch_track track)
+/**
+ * DWIMs a user-provided ref to determine the starting point for a
+ * branch and validates it, where:
+ *
+ * - r is the repository to validate the branch for
+ *
+ * - start_name is the ref that we would like to test. This is
+ * expanded with DWIM and assigned to out_real_ref.
+ *
+ * - track is the tracking mode of the new branch. If tracking is
+ * explicitly requested, start_name must be a branch (because
+ * otherwise start_name cannot be tracked)
+ *
+ * - out_oid is an out parameter containing the object_id of start_name
+ *
+ * - out_real_ref is an out parameter containing the full, 'real' form
+ * of start_name e.g. refs/heads/main instead of main
+ *
+ */
+static void dwim_branch_start(struct repository *r, const char *start_name,
+ enum branch_track track, char **out_real_ref,
+ struct object_id *out_oid)
{
struct commit *commit;
struct object_id oid;
char *real_ref;
- struct strbuf ref = STRBUF_INIT;
- int forcing = 0;
- int dont_change_ref = 0;
int explicit_tracking = 0;
if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
explicit_tracking = 1;
- if ((track == BRANCH_TRACK_OVERRIDE || clobber_head_ok)
- ? validate_branchname(name, &ref)
- : validate_new_branchname(name, &ref, force)) {
- if (!force)
- dont_change_ref = 1;
- else
- forcing = 1;
- }
-
real_ref = NULL;
if (get_oid_mb(start_name, &oid)) {
if (explicit_tracking) {
@@ -401,7 +410,34 @@ void create_branch(struct repository *r,
if ((commit = lookup_commit_reference(r, &oid)) == NULL)
die(_("not a valid branch point: '%s'"), start_name);
- oidcpy(&oid, &commit->object.oid);
+ if (out_real_ref)
+ *out_real_ref = real_ref ? xstrdup(real_ref) : NULL;
+ if (out_oid)
+ oidcpy(out_oid, &commit->object.oid);
+
+ FREE_AND_NULL(real_ref);
+}
+
+void create_branch(struct repository *r, const char *name,
+ const char *start_name, int force, int clobber_head_ok,
+ int reflog, int quiet, enum branch_track track)
+{
+ struct object_id oid;
+ char *real_ref;
+ struct strbuf ref = STRBUF_INIT;
+ int forcing = 0;
+ int dont_change_ref = 0;
+
+ if ((track == BRANCH_TRACK_OVERRIDE || clobber_head_ok)
+ ? validate_branchname(name, &ref)
+ : validate_new_branchname(name, &ref, force)) {
+ if (!force)
+ dont_change_ref = 1;
+ else
+ forcing = 1;
+ }
+
+ dwim_branch_start(r, start_name, track, &real_ref, &oid);
if (reflog)
log_all_ref_updates = LOG_REFS_NORMAL;
@@ -435,6 +471,15 @@ void create_branch(struct repository *r,
free(real_ref);
}
+void dwim_and_setup_tracking(struct repository *r, const char *new_ref,
+ const char *orig_ref, enum branch_track track,
+ int quiet)
+{
+ char *real_orig_ref;
+ dwim_branch_start(r, orig_ref, track, &real_orig_ref, NULL);
+ setup_tracking(new_ref, real_orig_ref, track, quiet);
+}
+
void remove_merge_branch_state(struct repository *r)
{
unlink(git_path_merge_head(r));
diff --git a/branch.h b/branch.h
index 815dcd40c0..ab2315c611 100644
--- a/branch.h
+++ b/branch.h
@@ -18,6 +18,28 @@ extern enum branch_track git_branch_track;
/* Functions for acting on the information about branches. */
+/**
+ * Sets branch.<new_ref>.{remote,merge} config settings such that
+ * new_ref tracks orig_ref according to the specified tracking mode.
+ *
+ * - new_ref is the name of the branch that we are setting tracking
+ * for.
+ *
+ * - orig_ref is the name of the ref that is 'upstream' of new_ref.
+ * orig_ref will be expanded with DWIM so that the config settings
+ * are in the correct format e.g. "refs/remotes/origin/main" instead
+ * of "origin/main".
+ *
+ * - track is the tracking mode e.g. BRANCH_TRACK_REMOTE causes
+ * new_ref to track orig_ref directly, whereas BRANCH_TRACK_INHERIT
+ * causes new_ref to track whatever orig_ref tracks.
+ *
+ * - quiet suppresses tracking information.
+ */
+void dwim_and_setup_tracking(struct repository *r, const char *new_ref,
+ const char *orig_ref, enum branch_track track,
+ int quiet);
+
/*
* Creates a new branch, where:
*
diff --git a/builtin/branch.c b/builtin/branch.c
index e99bdae897..4a9e0f5727 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -828,12 +828,9 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
if (!ref_exists(branch->refname))
die(_("branch '%s' does not exist"), branch->name);
- /*
- * create_branch takes care of setting up the tracking
- * info and making sure new_upstream is correct
- */
- create_branch(the_repository, branch->name, new_upstream,
- 0, 0, 0, quiet, BRANCH_TRACK_OVERRIDE);
+ dwim_and_setup_tracking(the_repository, branch->name,
+ new_upstream, BRANCH_TRACK_OVERRIDE,
+ quiet);
} else if (unset_upstream) {
struct branch *branch = branch_get(argv[0]);
struct strbuf buf = STRBUF_INIT;
--
2.33.GIT
