The interpret_branch_name() function converts names like
@{-1} and @{upstream} into branch names. The expanded ref
names are not fully qualified, and may be outside of the
refs/heads/ namespace (e.g., "@" expands to "HEAD", and
"@{upstream}" is likely to be in "refs/remotes/").
This is OK for callers like dwim_ref() which are primarily
interested in resolving the resulting name, no matter where
it is. But callers like "git branch" treat the result as a
branch name in refs/heads/. When we expand to a ref outside
that namespace, the results are very confusing (e.g., "git
branch @" tries to create refs/heads/HEAD, which is
nonsense).
Callers can't know from the returned string how the
expansion happened (e.g., did the user really ask for a
branch named "HEAD", or did we do a bogus expansion?). One
fix would be to return some out-parameters describing the
types of expansion that occurred. This has the benefit that
the caller can generate precise error messages ("I
understood @{upstream} to mean origin/master, but that is a
remote tracking branch, so you cannot create it as a local
name").
However, out-parameters make the function interface somewhat
cumbersome. Instead, let's do the opposite: let the caller
tell us which elements to expand. That's easier to pass in,
and none of the callers give more precise error messages
than "@{upstream} isn't a valid branch name" anyway (which
should be sufficient).
The strbuf_branchname() function needs a similar parameter,
as most of the callers access interpret_branch_name()
through it.
We can break the callers down into two groups:
1. Callers that are happy with any kind of ref in the
result. We pass "0" here, so they continue to work
without restrictions. This includes merge_name(),
the reflog handling in add_pending_object_with_path(),
and substitute_branch_name(). This last is what powers
dwim_ref().
2. Callers that have funny corner cases (mostly in
git-branch and git-checkout). These need to make use of
the new parameter, but I've left them as "0" in this
patch, and will address them individually in follow-on
patches.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
builtin/branch.c | 2 +-
builtin/checkout.c | 2 +-
builtin/merge.c | 2 +-
cache.h | 13 +++++++++--
refs.c | 2 +-
revision.c | 2 +-
sha1_name.c | 68 ++++++++++++++++++++++++++++++++++++++----------------
strbuf.h | 6 ++++-
8 files changed, 69 insertions(+), 28 deletions(-)
diff --git a/builtin/branch.c b/builtin/branch.c
index 94f7de7fa..cf0ece55d 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -216,7 +216,7 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
char *target = NULL;
int flags = 0;
- strbuf_branchname(&bname, argv[i]);
+ strbuf_branchname(&bname, argv[i], 0);
free(name);
name = mkpathdup(fmt, bname.buf);
diff --git a/builtin/checkout.c b/builtin/checkout.c
index f174f5030..05eefd994 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -452,7 +452,7 @@ static void setup_branch_path(struct branch_info *branch)
{
struct strbuf buf = STRBUF_INIT;
- strbuf_branchname(&buf, branch->name);
+ strbuf_branchname(&buf, branch->name, 0);
if (strcmp(buf.buf, branch->name))
branch->name = xstrdup(buf.buf);
strbuf_splice(&buf, 0, 0, "refs/heads/", 11);
diff --git a/builtin/merge.c b/builtin/merge.c
index a96d4fb50..848a29855 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -438,7 +438,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
char *found_ref;
int len, early;
- strbuf_branchname(&bname, remote);
+ strbuf_branchname(&bname, remote, 0);
remote = bname.buf;
memset(branch_head, 0, sizeof(branch_head));
diff --git a/cache.h b/cache.h
index c67995caa..a8816c914 100644
--- a/cache.h
+++ b/cache.h
@@ -1383,8 +1383,17 @@ extern char *oid_to_hex(const struct object_id *oid); /* same static buffer as s
*
* If the input was ok but there are not N branch switches in the
* reflog, it returns 0.
- */
-extern int interpret_branch_name(const char *str, int len, struct strbuf *);
+ *
+ * If "allowed" is non-zero, it is a treated as a bitfield of allowable
+ * expansions: local branches ("refs/heads/"), remote branches
+ * ("refs/remotes/"), or "HEAD". If no "allowed" bits are set, any expansion is
+ * allowed, even ones to refs outside of those namespaces.
+ */
+#define INTERPRET_BRANCH_LOCAL (1<<0)
+#define INTERPRET_BRANCH_REMOTE (1<<1)
+#define INTERPRET_BRANCH_HEAD (1<<2)
+extern int interpret_branch_name(const char *str, int len, struct strbuf *,
+ unsigned allowed);
extern int get_oid_mb(const char *str, struct object_id *oid);
extern int validate_headref(const char *ref);
diff --git a/refs.c b/refs.c
index 6d0961921..da62119c2 100644
--- a/refs.c
+++ b/refs.c
@@ -405,7 +405,7 @@ int refname_match(const char *abbrev_name, const char *full_name)
static char *substitute_branch_name(const char **string, int *len)
{
struct strbuf buf = STRBUF_INIT;
- int ret = interpret_branch_name(*string, *len, &buf);
+ int ret = interpret_branch_name(*string, *len, &buf, 0);
if (ret == *len) {
size_t size;
diff --git a/revision.c b/revision.c
index b37dbec37..771d079f6 100644
--- a/revision.c
+++ b/revision.c
@@ -147,7 +147,7 @@ static void add_pending_object_with_path(struct rev_info *revs,
revs->no_walk = 0;
if (revs->reflog_info && obj->type == OBJ_COMMIT) {
struct strbuf buf = STRBUF_INIT;
- int len = interpret_branch_name(name, 0, &buf);
+ int len = interpret_branch_name(name, 0, &buf, 0);
int st;
if (0 < len && name[len] && buf.len)
diff --git a/sha1_name.c b/sha1_name.c
index 4c1e91184..7f754b60c 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1176,7 +1176,8 @@ static int interpret_empty_at(const char *name, int namelen, int len, struct str
return 1;
}
-static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
+static int reinterpret(const char *name, int namelen, int len,
+ struct strbuf *buf, unsigned allowed)
{
/* we have extra data, which might need further processing */
struct strbuf tmp = STRBUF_INIT;
@@ -1184,7 +1185,7 @@ static int reinterpret(const char *name, int namelen, int len, struct strbuf *bu
int ret;
strbuf_add(buf, name + len, namelen - len);
- ret = interpret_branch_name(buf->buf, buf->len, &tmp);
+ ret = interpret_branch_name(buf->buf, buf->len, &tmp, allowed);
/* that data was not interpreted, remove our cruft */
if (ret < 0) {
strbuf_setlen(buf, used);
@@ -1205,11 +1206,27 @@ static void set_shortened_ref(struct strbuf *buf, const char *ref)
free(s);
}
+static int branch_interpret_allowed(const char *refname, unsigned allowed)
+{
+ if (!allowed)
+ return 1;
+
+ if ((allowed & INTERPRET_BRANCH_LOCAL) &&
+ starts_with(refname, "refs/heads/"))
+ return 1;
+ if ((allowed & INTERPRET_BRANCH_REMOTE) &&
+ starts_with(refname, "refs/remotes/"))
+ return 1;
+
+ return 0;
+}
+
static int interpret_branch_mark(const char *name, int namelen,
int at, struct strbuf *buf,
int (*get_mark)(const char *, int),
const char *(*get_data)(struct branch *,
- struct strbuf *))
+ struct strbuf *),
+ unsigned allowed)
{
int len;
struct branch *branch;
@@ -1234,11 +1251,15 @@ static int interpret_branch_mark(const char *name, int namelen,
if (!value)
die("%s", err.buf);
+ if (!branch_interpret_allowed(value, allowed))
+ return -1;
+
set_shortened_ref(buf, value);
return len + at;
}
-int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
+int interpret_branch_name(const char *name, int namelen, struct strbuf *buf,
+ unsigned allowed)
{
char *at;
const char *start;
@@ -1247,31 +1268,38 @@ int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
if (!namelen)
namelen = strlen(name);
- len = interpret_nth_prior_checkout(name, namelen, buf);
- if (!len) {
- return len; /* syntax Ok, not enough switches */
- } else if (len > 0) {
- if (len == namelen)
- return len; /* consumed all */
- else
- return reinterpret(name, namelen, len, buf);
+ if (!allowed || (allowed & INTERPRET_BRANCH_LOCAL)) {
+ len = interpret_nth_prior_checkout(name, namelen, buf);
+ if (!len) {
+ return len; /* syntax Ok, not enough switches */
+ } else if (len > 0) {
+ if (len == namelen)
+ return len; /* consumed all */
+ else
+ return reinterpret(name, namelen, len, buf, allowed);
+ }
}
for (start = name;
(at = memchr(start, '@', namelen - (start - name)));
start = at + 1) {
- len = interpret_empty_at(name, namelen, at - name, buf);
- if (len > 0)
- return reinterpret(name, namelen, len, buf);
+ if (!allowed || (allowed & INTERPRET_BRANCH_HEAD)) {
+ len = interpret_empty_at(name, namelen, at - name, buf);
+ if (len > 0)
+ return reinterpret(name, namelen, len, buf,
+ allowed);
+ }
len = interpret_branch_mark(name, namelen, at - name, buf,
- upstream_mark, branch_get_upstream);
+ upstream_mark, branch_get_upstream,
+ allowed);
if (len > 0)
return len;
len = interpret_branch_mark(name, namelen, at - name, buf,
- push_mark, branch_get_push);
+ push_mark, branch_get_push,
+ allowed);
if (len > 0)
return len;
}
@@ -1279,10 +1307,10 @@ int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
return -1;
}
-void strbuf_branchname(struct strbuf *sb, const char *name)
+void strbuf_branchname(struct strbuf *sb, const char *name, unsigned allowed)
{
int len = strlen(name);
- int used = interpret_branch_name(name, len, sb);
+ int used = interpret_branch_name(name, len, sb, allowed);
if (used < 0)
used = 0;
@@ -1291,7 +1319,7 @@ void strbuf_branchname(struct strbuf *sb, const char *name)
int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
{
- strbuf_branchname(sb, name);
+ strbuf_branchname(sb, name, 0);
if (name[0] == '-')
return -1;
strbuf_splice(sb, 0, 0, "refs/heads/", 11);
diff --git a/strbuf.h b/strbuf.h
index 6b51b2604..17e5f29a5 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -567,8 +567,12 @@ static inline void strbuf_complete_line(struct strbuf *sb)
* "refs/remotes/origin/master").
*
* Note that the resulting name may not be a syntactically valid refname.
+ *
+ * If "allowed" is non-zero, restrict the set of allowed expansions. See
+ * interpret_branch_name() for details.
*/
-extern void strbuf_branchname(struct strbuf *sb, const char *name);
+extern void strbuf_branchname(struct strbuf *sb, const char *name,
+ unsigned allowed);
/*
* Like strbuf_branchname() above, but confirm that the result is
--
2.12.0.367.gb23790f66