[PATCH 02/12] name-hash: add index_dir_exists2()

From: Jeff Hostetler via GitGitGadget <gitgitgadget@gmail.com>
Date: Feb 13, 2024, 20:52 UTC
Message-ID: <3464545fe3feceb08408618c77a70cc95745bfe9.1707857541.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.1662.git.1707857541.gitgitgadget@gmail.com>

From: Jeff Hostetler <jeffhostetler@github.com>

Create a new version of index_dir_exists() to return the canonical spelling of the matched directory prefix.

The existing index_dir_exists() returns a boolean to indicate if there is a case-insensitive match in the directory name-hash, but it doesn't tell the caller the exact spelling of that match.

The new version also copies the matched spelling to a provided strbuf. This lets the caller, for example, then call index_name_pos() with the correct case to search the cache-entry array for the real insertion position.

Signed-off-by: Jeff Hostetler <jeffhostetler@github.com>
---
 name-hash.c | 16 ++++++++++++++++
 name-hash.h |  2 ++
 2 files changed, 18 insertions(+)

diff --git a/name-hash.c b/name-hash.c
index 251f036eef6..d735c81acb3 100644
--- a/name-hash.c
+++ b/name-hash.c
@@ -694,6 +694,22 @@ int index_dir_exists(struct index_state *istate, const char *name, int namelen)
 	dir = find_dir_entry(istate, name, namelen);
 	return dir && dir->nr;
 }
+int index_dir_exists2(struct index_state *istate, const char *name, int namelen,
+		      struct strbuf *canonical_path)
+{
+	struct dir_entry *dir;
+
+	strbuf_init(canonical_path, namelen+1);
+
+	lazy_init_name_hash(istate);
+	expand_to_path(istate, name, namelen, 0);
+	dir = find_dir_entry(istate, name, namelen);
+
+	if (dir && dir->nr)
+		strbuf_add(canonical_path, dir->name, dir->namelen);
+
+	return dir && dir->nr;
+}
 
 void adjust_dirname_case(struct index_state *istate, char *name)
 {
diff --git a/name-hash.h b/name-hash.h
index b1b4b0fb337..2fcac5c4870 100644
--- a/name-hash.h
+++ b/name-hash.h
@@ -5,6 +5,8 @@ struct cache_entry;
 struct index_state;
 
 int index_dir_exists(struct index_state *istate, const char *name, int namelen);
+int index_dir_exists2(struct index_state *istate, const char *name, int namelen,
+		      struct strbuf *canonical_path);
 void adjust_dirname_case(struct index_state *istate, char *name);
 struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);

-- 
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