[PATCH v2 09/13] setup: propagate prefix via repository discovery

[Patrick Steinhardt <ps@pks.im>]

In the preceding commits we have started to propagate all information
required for the configuration of the repository via a new `struct
repo_discovery`. The only exception is the repository's prefix, which we
still return via the return parameter.

This is conceptually fine, but somewhat inconsistent. Refactor this to
instead propagate the prefix via the repository discovery, too.

While at it, drop a static variable in `repo_discover_bare_gitdir()`.
We apply its value to the repository discovery anyway, so we don't have
to keep it around afterwards anymore.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 setup.c | 101 +++++++++++++++++++++++++++++-----------------------------------
 1 file changed, 45 insertions(+), 56 deletions(-)

diff --git a/setup.c b/setup.c
index f8e4cf100b..d1db0a4ca0 100644
--- a/setup.c
+++ b/setup.c
@@ -1094,6 +1094,7 @@ struct repo_discovery {
 	struct repository_format format;
 	char *gitdir;
 	char *worktree;
+	char *prefix;
 };
 
 #define REPO_DISCOVERY_INIT { \
@@ -1105,6 +1106,7 @@ static void repo_discovery_release(struct repo_discovery *r)
 	clear_repository_format(&r->format);
 	free(r->gitdir);
 	free(r->worktree);
+	free(r->prefix);
 }
 
 static void repo_discovery_set_gitdir(struct repo_discovery *r,
@@ -1128,10 +1130,10 @@ static void repo_discovery_set_worktree(struct repo_discovery *r,
 	r->worktree = real_pathdup(worktree, 1);
 }
 
-static const char *repo_discover_explicit_gitdir(struct repo_discovery *discovery,
-						 const char *gitdirenv,
-						 struct strbuf *cwd,
-						 int *nongit_ok)
+static void repo_discover_explicit_gitdir(struct repo_discovery *discovery,
+					  const char *gitdirenv,
+					  struct strbuf *cwd,
+					  int *nongit_ok)
 {
 	const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 	char *gitfile;
@@ -1149,16 +1151,13 @@ static const char *repo_discover_explicit_gitdir(struct repo_discovery *discover
 	if (!is_git_directory(gitdirenv)) {
 		if (nongit_ok) {
 			*nongit_ok = 1;
-			free(gitfile);
-			return NULL;
+			goto out;
 		}
 		die(_("not a git repository: '%s'"), gitdirenv);
 	}
 
-	if (read_and_verify_repository_format(&discovery->format, gitdirenv, nongit_ok)) {
-		free(gitfile);
-		return NULL;
-	}
+	if (read_and_verify_repository_format(&discovery->format, gitdirenv, nongit_ok))
+		goto out;
 
 	/* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 	if (work_tree_env) {
@@ -1173,8 +1172,7 @@ static const char *repo_discover_explicit_gitdir(struct repo_discovery *discover
 	} else if (discovery->format.is_bare > 0) {
 		/* #18, #26 */
 		repo_discovery_set_gitdir(discovery, gitdirenv, 0);
-		free(gitfile);
-		return NULL;
+		goto out;
 	} else if (discovery->format.work_tree) { /* #6, #14 */
 		if (is_absolute_path(discovery->format.work_tree)) {
 			repo_discovery_set_worktree(discovery, discovery->format.work_tree);
@@ -1193,8 +1191,7 @@ static const char *repo_discover_explicit_gitdir(struct repo_discovery *discover
 	} else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 		/* #16d */
 		repo_discovery_set_gitdir(discovery, gitdirenv, 0);
-		free(gitfile);
-		return NULL;
+		goto out;
 	} else { /* #2, #10 */
 		repo_discovery_set_worktree(discovery, ".");
 	}
@@ -1202,8 +1199,7 @@ static const char *repo_discover_explicit_gitdir(struct repo_discovery *discover
 	/* both the worktree and cwd are already normalized */
 	if (!strcmp(cwd->buf, discovery->worktree)) { /* cwd == worktree */
 		repo_discovery_set_gitdir(discovery, gitdirenv, 0);
-		free(gitfile);
-		return NULL;
+		goto out;
 	}
 
 	offset = dir_inside_of(cwd->buf, discovery->worktree);
@@ -1211,38 +1207,37 @@ static const char *repo_discover_explicit_gitdir(struct repo_discovery *discover
 		repo_discovery_set_gitdir(discovery, gitdirenv, 1);
 		if (chdir(discovery->worktree))
 			die_errno(_("cannot chdir to '%s'"), discovery->worktree);
-		strbuf_addch(cwd, '/');
-		free(gitfile);
-		return cwd->buf + offset;
+		discovery->prefix = xstrfmt("%s/", cwd->buf + offset);
+		goto out;
 	}
 
 	/* cwd outside worktree */
 	repo_discovery_set_gitdir(discovery, gitdirenv, 0);
+
+out:
 	free(gitfile);
-	return NULL;
 }
 
-static const char *repo_discover_implicit_gitdir(struct repo_discovery *discovery,
-						 const char *gitdir,
-						 struct strbuf *cwd, int offset,
-						 int *nongit_ok)
+static void repo_discover_implicit_gitdir(struct repo_discovery *discovery,
+					  const char *gitdir,
+					  struct strbuf *cwd, int offset,
+					  int *nongit_ok)
 {
 	if (read_and_verify_repository_format(&discovery->format, gitdir, nongit_ok))
-		return NULL;
+		return;
 
 	/* --work-tree is set without --git-dir; use discovered one */
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || discovery->format.work_tree) {
 		char *to_free = NULL;
-		const char *ret;
 
 		if (offset != cwd->len && !is_absolute_path(gitdir))
 			gitdir = to_free = real_pathdup(gitdir, 1);
 		if (chdir(cwd->buf))
 			die_errno(_("cannot come back to cwd"));
-		ret = repo_discover_explicit_gitdir(discovery, gitdir, cwd,
-						    nongit_ok);
+		repo_discover_explicit_gitdir(discovery, gitdir, cwd,
+					      nongit_ok);
 		free(to_free);
-		return ret;
+		return;
 	}
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
@@ -1250,7 +1245,7 @@ static const char *repo_discover_implicit_gitdir(struct repo_discovery *discover
 		repo_discovery_set_gitdir(discovery, gitdir, (offset != cwd->len));
 		if (chdir(cwd->buf))
 			die_errno(_("cannot come back to cwd"));
-		return NULL;
+		return;
 	}
 
 	/* #0, #1, #5, #8, #9, #12, #13 */
@@ -1258,37 +1253,34 @@ static const char *repo_discover_implicit_gitdir(struct repo_discovery *discover
 	if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 		repo_discovery_set_gitdir(discovery, gitdir, 0);
 	if (offset >= cwd->len)
-		return NULL;
+		return;
 
 	/* Make "offset" point past the '/' (already the case for root dirs) */
 	if (offset != offset_1st_component(cwd->buf))
 		offset++;
-	/* Add a '/' at the end */
-	strbuf_addch(cwd, '/');
-	return cwd->buf + offset;
+	discovery->prefix = xstrfmt("%s/", cwd->buf + offset);
 }
 
 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
-static const char *repo_discover_bare_gitdir(struct repo_discovery *discovery,
-					     struct strbuf *cwd, int offset,
-					     int *nongit_ok)
+static void repo_discover_bare_gitdir(struct repo_discovery *discovery,
+				      struct strbuf *cwd, int offset,
+				      int *nongit_ok)
 {
 	int root_len;
 
 	if (read_and_verify_repository_format(&discovery->format, ".", nongit_ok))
-		return NULL;
+		return;
 
 	setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 
 	/* --work-tree is set without --git-dir; use discovered one */
 	if (getenv(GIT_WORK_TREE_ENVIRONMENT) || discovery->format.work_tree) {
-		static const char *gitdir;
-
-		gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
+		char *gitdir = offset == cwd->len ? xstrdup(".") : xmemdupz(cwd->buf, offset);
 		if (chdir(cwd->buf))
 			die_errno(_("cannot come back to cwd"));
-		return repo_discover_explicit_gitdir(discovery, gitdir, cwd,
-						     nongit_ok);
+		repo_discover_explicit_gitdir(discovery, gitdir, cwd, nongit_ok);
+		free(gitdir);
+		return;
 	}
 
 	if (offset != cwd->len) {
@@ -1297,10 +1289,9 @@ static const char *repo_discover_bare_gitdir(struct repo_discovery *discovery,
 		root_len = offset_1st_component(cwd->buf);
 		strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 		repo_discovery_set_gitdir(discovery, cwd->buf, 0);
-	}
-	else
+	} else {
 		repo_discovery_set_gitdir(discovery, ".", 0);
-	return NULL;
+	}
 }
 
 static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
@@ -1936,7 +1927,6 @@ const char *setup_git_directory_gently(struct repository *repo, int *nongit_ok)
 	struct strbuf cwd = STRBUF_INIT;
 	struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT, report = STRBUF_INIT;
 	struct repo_discovery discovery = REPO_DISCOVERY_INIT;
-	const char *prefix = NULL;
 
 	/*
 	 * We may have read an incomplete configuration before
@@ -1961,20 +1951,19 @@ const char *setup_git_directory_gently(struct repository *repo, int *nongit_ok)
 
 	switch (repo_discovery_find_dir(&dir, &gitdir, &report, 1)) {
 	case GIT_DIR_EXPLICIT:
-		prefix = repo_discover_explicit_gitdir(&discovery, gitdir.buf, &cwd,
-						       nongit_ok);
+		repo_discover_explicit_gitdir(&discovery, gitdir.buf, &cwd,
+					      nongit_ok);
 		break;
 	case GIT_DIR_DISCOVERED:
 		if (dir.len < cwd.len && chdir(dir.buf))
 			die(_("cannot change to '%s'"), dir.buf);
-		prefix = repo_discover_implicit_gitdir(&discovery, gitdir.buf, &cwd, dir.len,
-						       nongit_ok);
+		repo_discover_implicit_gitdir(&discovery, gitdir.buf, &cwd, dir.len,
+					      nongit_ok);
 		break;
 	case GIT_DIR_BARE:
 		if (dir.len < cwd.len && chdir(dir.buf))
 			die(_("cannot change to '%s'"), dir.buf);
-		prefix = repo_discover_bare_gitdir(&discovery, &cwd, dir.len,
-						   nongit_ok);
+		repo_discover_bare_gitdir(&discovery, &cwd, dir.len, nongit_ok);
 		break;
 	case GIT_DIR_HIT_CEILING:
 		if (!nongit_ok)
@@ -2103,10 +2092,10 @@ const char *setup_git_directory_gently(struct repository *repo, int *nongit_ok)
 	 * out where the repository is, i.e. a preparation
 	 * for calling repo_config_get_bool().
 	 */
-	if (prefix) {
-		prefix = precompose_string_if_needed(prefix);
+	if (discovery.prefix) {
+		const char *prefix = precompose_string_if_needed(discovery.prefix);
 		repo->prefix = xstrdup(prefix);
-		setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
+		setenv(GIT_PREFIX_ENVIRONMENT, repo->prefix, 1);
 	} else {
 		FREE_AND_NULL(repo->prefix);
 		setenv(GIT_PREFIX_ENVIRONMENT, "", 1);

-- 
2.55.0.141.g00534a21ce.dirty