Merge branch 'jc/branch-name-sanity'

"git branch" and "git checkout -b" are now forbidden from creating
a branch whose name is "HEAD".

* jc/branch-name-sanity:
builtin/branch: remove redundant check for HEAD
branch: correctly reject refs/heads/{-dash,HEAD}
branch: split validate_new_branchname() into two
branch: streamline "attr_only" handling in validate_new_branchname()

diff --git a/branch.c b/branch.c
index 62f7b0d8c2d6a89fde5abffb6c836d0ce7706ac4..fe1e1c3676b26a4f35feaf8137700b25916ad5ee 100644 (file)
--- a/branch.c
+++ b/branch.c
@@ -178,24 +178,40 @@ int read_branch_desc(struct strbuf *buf, const char *branch_name)
        return 0;
 }
 
-int validate_new_branchname(const char *name, struct strbuf *ref,
-                           int force, int attr_only)
+/*
+ * Check if 'name' can be a valid name for a branch; die otherwise.
+ * Return 1 if the named branch already exists; return 0 otherwise.
+ * Fill ref with the full refname for the branch.
+ */
+int validate_branchname(const char *name, struct strbuf *ref)
 {
        if (strbuf_check_branch_ref(ref, name))
                die(_("'%s' is not a valid branch name."), name);
 
-       if (!ref_exists(ref->buf))
+       return ref_exists(ref->buf);
+}
+
+/*
+ * Check if a branch 'name' can be created as a new branch; die otherwise.
+ * 'force' can be used when it is OK for the named branch already exists.
+ * Return 1 if the named branch already exists; return 0 otherwise.
+ * Fill ref with the full refname for the branch.
+ */
+int validate_new_branchname(const char *name, struct strbuf *ref, int force)
+{
+       const char *head;
+
+       if (!validate_branchname(name, ref))
                return 0;
-       else if (!force && !attr_only)
-               die(_("A branch named '%s' already exists."), ref->buf + strlen("refs/heads/"));
 
-       if (!attr_only) {
-               const char *head;
+       if (!force)
+               die(_("A branch named '%s' already exists."),
+                   ref->buf + strlen("refs/heads/"));
+
+       head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
+       if (!is_bare_repository() && head && !strcmp(head, ref->buf))
+               die(_("Cannot force update the current branch."));
 
-               head = resolve_ref_unsafe("HEAD", 0, NULL, NULL);
-               if (!is_bare_repository() && head && !strcmp(head, ref->buf))
-                       die(_("Cannot force update the current branch."));
-       }
        return 1;
 }
 
@@ -242,9 +258,9 @@ void create_branch(const char *name, const char *start_name,
        if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
                explicit_tracking = 1;
 
-       if (validate_new_branchname(name, &ref, force,
-                                   track == BRANCH_TRACK_OVERRIDE ||
-                                   clobber_head)) {
+       if ((track == BRANCH_TRACK_OVERRIDE || clobber_head)
+           ? validate_branchname(name, &ref)
+           : validate_new_branchname(name, &ref, force)) {
                if (!force)
                        dont_change_ref = 1;
                else

diff --git a/branch.h b/branch.h
index b07788558c0e76a701b571f73c0462dcf2abcc63..be5e5d13083a98e57e834d81afe5450f11202130 100644 (file)
--- a/branch.h
+++ b/branch.h
@@ -23,22 +23,19 @@ void create_branch(const char *name, const char *start_name,
                   int clobber_head, int quiet, enum branch_track track);
 
 /*
- * Validates that the requested branch may be created, returning the
- * interpreted ref in ref, force indicates whether (non-head) branches
- * may be overwritten. A non-zero return value indicates that the force
- * parameter was non-zero and the branch already exists.
- *
- * Contrary to all of the above, when attr_only is 1, the caller is
- * not interested in verifying if it is Ok to update the named
- * branch to point at a potentially different commit. It is merely
- * asking if it is OK to change some attribute for the named branch
- * (e.g. tracking upstream).
- *
- * NEEDSWORK: This needs to be split into two separate functions in the
- * longer run for sanity.
- *
+ * Check if 'name' can be a valid name for a branch; die otherwise.
+ * Return 1 if the named branch already exists; return 0 otherwise.
+ * Fill ref with the full refname for the branch.
+ */
+extern int validate_branchname(const char *name, struct strbuf *ref);
+
+/*
+ * Check if a branch 'name' can be created as a new branch; die otherwise.
+ * 'force' can be used when it is OK for the named branch already exists.
+ * Return 1 if the named branch already exists; return 0 otherwise.
+ * Fill ref with the full refname for the branch.
  */
-int validate_new_branchname(const char *name, struct strbuf *ref, int force, int attr_only);
+extern int validate_new_branchname(const char *name, struct strbuf *ref, int force);
 
 /*
  * Remove information about the state of working on the current

diff --git a/builtin/branch.c b/builtin/branch.c
index 33fd5fcfd10be978f4d8ccdb6869eb05e86eb956..5fc57cdc982f86d6e449d8358004c476707d909c 100644 (file)
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -463,7 +463,6 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
        struct strbuf oldref = STRBUF_INIT, newref = STRBUF_INIT, logmsg = STRBUF_INIT;
        struct strbuf oldsection = STRBUF_INIT, newsection = STRBUF_INIT;
        int recovery = 0;
-       int clobber_head_ok;
 
        if (!oldname) {
                if (copy)
@@ -487,9 +486,10 @@ static void copy_or_rename_branch(const char *oldname, const char *newname, int
         * A command like "git branch -M currentbranch currentbranch" cannot
         * cause the worktree to become inconsistent with HEAD, so allow it.
         */
-       clobber_head_ok = !strcmp(oldname, newname);
-
-       validate_new_branchname(newname, &newref, force, clobber_head_ok);
+       if (!strcmp(oldname, newname))
+               validate_branchname(newname, &newref);
+       else
+               validate_new_branchname(newname, &newref, force);
 
        reject_rebase_or_bisect_branch(oldref.buf);
 
@@ -793,9 +793,6 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
        } else if (argc > 0 && argc <= 2) {
                struct branch *branch = branch_get(argv[0]);
 
-               if (!strcmp(argv[0], "HEAD"))
-                       die(_("it does not make sense to create 'HEAD' manually"));
-
                if (!branch)
                        die(_("no such branch '%s'"), argv[0]);
 

diff --git a/builtin/checkout.c b/builtin/checkout.c
index 7d8bcc3833512bc262bd0a8d86db9169d991b320..3faae382de4fa345f6d54c9120d33ed86c02e2cc 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1287,11 +1287,11 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
        if (opts.new_branch) {
                struct strbuf buf = STRBUF_INIT;
 
-               opts.branch_exists =
-                       validate_new_branchname(opts.new_branch, &buf,
-                                               !!opts.new_branch_force,
-                                               !!opts.new_branch_force);
-
+               if (opts.new_branch_force)
+                       opts.branch_exists = validate_branchname(opts.new_branch, &buf);
+               else
+                       opts.branch_exists =
+                               validate_new_branchname(opts.new_branch, &buf, 0);
                strbuf_release(&buf);
        }
 

diff --git a/sha1_name.c b/sha1_name.c
index 9a2d5caf3b785ec629fcbc2325cd63e0ef72cf57..611c7d24ddee678470ba74cb3c2ca669a778b44a 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -1438,9 +1438,19 @@ int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
                strbuf_branchname(sb, name, INTERPRET_BRANCH_LOCAL);
        else
                strbuf_addstr(sb, name);
-       if (name[0] == '-')
-               return -1;
+
+       /*
+        * This splice must be done even if we end up rejecting the
+        * name; builtin/branch.c::copy_or_rename_branch() still wants
+        * to see what the name expanded to so that "branch -m" can be
+        * used as a tool to correct earlier mistakes.
+        */
        strbuf_splice(sb, 0, 0, "refs/heads/", 11);
+
+       if (*name == '-' ||
+           !strcmp(sb->buf, "refs/heads/HEAD"))
+               return -1;
+
        return check_refname_format(sb->buf, 0);
 }
 

diff --git a/t/t1430-bad-ref-name.sh b/t/t1430-bad-ref-name.sh
index e88349c8a0483b97ea38013de61d799003fd85b5..c7878a60edfdcf24f3c45367f58e62b0ce6dab71 100755 (executable)
--- a/t/t1430-bad-ref-name.sh
+++ b/t/t1430-bad-ref-name.sh
@@ -331,4 +331,47 @@ test_expect_success 'update-ref --stdin -z fails delete with bad ref name' '
        grep "fatal: invalid ref format: ~a" err
 '
 
+test_expect_success 'branch rejects HEAD as a branch name' '
+       test_must_fail git branch HEAD HEAD^ &&
+       test_must_fail git show-ref refs/heads/HEAD
+'
+
+test_expect_success 'checkout -b rejects HEAD as a branch name' '
+       test_must_fail git checkout -B HEAD HEAD^ &&
+       test_must_fail git show-ref refs/heads/HEAD
+'
+
+test_expect_success 'update-ref can operate on refs/heads/HEAD' '
+       git update-ref refs/heads/HEAD HEAD^ &&
+       git show-ref refs/heads/HEAD &&
+       git update-ref -d refs/heads/HEAD &&
+       test_must_fail git show-ref refs/heads/HEAD
+'
+
+test_expect_success 'branch -d can remove refs/heads/HEAD' '
+       git update-ref refs/heads/HEAD HEAD^ &&
+       git branch -d HEAD &&
+       test_must_fail git show-ref refs/heads/HEAD
+'
+
+test_expect_success 'branch -m can rename refs/heads/HEAD' '
+       git update-ref refs/heads/HEAD HEAD^ &&
+       git branch -m HEAD tail &&
+       test_must_fail git show-ref refs/heads/HEAD &&
+       git show-ref refs/heads/tail
+'
+
+test_expect_success 'branch -d can remove refs/heads/-dash' '
+       git update-ref refs/heads/-dash HEAD^ &&
+       git branch -d -- -dash &&
+       test_must_fail git show-ref refs/heads/-dash
+'
+
+test_expect_success 'branch -m can rename refs/heads/-dash' '
+       git update-ref refs/heads/-dash HEAD^ &&
+       git branch -m -- -dash dash &&
+       test_must_fail git show-ref refs/heads/-dash &&
+       git show-ref refs/heads/dash
+'
+
 test_done