Subject: [PATCH] sparse-index: pass string length to index_file_exists()

From: "Jeff Hostetler via GitGitGadget" <[email-masked]>
Date: Fri, 02 Feb 2024 18:04:54 +0000

From: Jeff Hostetler <[email-masked]>

The call to index_file_exists() in the loop in expand_to_path() passes
the wrong string length.  Let's fix that.

The loop in expand_to_path() searches the name-hash for each
sub-directory prefix in the provided pathname. That is, by searching
for "dir1/" then "dir1/dir2/" then "dir1/dir2/dir3/" and so on until
it finds a cache-entry representing a sparse directory.

The code creates "strbuf path_mutable" to contain the working pathname
and modifies the buffer in-place by temporarily replacing the character
following each successive "/" with NUL for the duration of the call to
index_file_exists().

It does not update the strbuf.len during this substitution.

Pass the patched length of the prefix path instead.

Signed-off-by: Jeff Hostetler <[email-masked]>
---
    sparse-index: pass string length to index_file_exists()
    
    The call to index_file_exists() in the loop in expand_to_path() passes
    the wrong string length. Let's fix that.
    
    The loop in expand_to_path() searches the name-hash for each
    sub-directory prefix in the provided pathname. That is, by searching for
    "dir1/" then "dir1/dir2/" then "dir1/dir2/dir3/" and so on until it
    finds a cache-entry representing a sparse directory.
    
    The code creates "strbuf path_mutable" to contain the working pathname
    and modifies the buffer in-place by temporarily replacing the character
    following each successive "/" with NUL for the duration of the call to
    index_file_exists().
    
    It does not update the strbuf.len during this substitution.
    
    Pass the patched length of the prefix path instead.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1649%2Fjeffhostetler%2Fsparse-index-string-length-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1649/jeffhostetler/sparse-index-string-length-v1
Pull-Request: https://github.com/gitgitgadget/git/pull/1649

 sparse-index.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sparse-index.c b/sparse-index.c
index 1fdb07a9e69..093708f6220 100644
--- a/sparse-index.c
+++ b/sparse-index.c
@@ -579,8 +579,9 @@ void expand_to_path(struct index_state *istate,
 		replace++;
 		temp = *replace;
 		*replace = '\0';
+		substr_len = replace - path_mutable.buf;
 		if (index_file_exists(istate, path_mutable.buf,
-				      path_mutable.len, icase)) {
+				      substr_len, icase)) {
 			/*
 			 * We found a parent directory in the name-hash
 			 * hashtable, because only sparse directory entries
@@ -593,7 +594,6 @@ void expand_to_path(struct index_state *istate,
 		}
 
 		*replace = temp;
-		substr_len = replace - path_mutable.buf;
 	}
 
 cleanup:

base-commit: 43c8a30d150ecede9709c1f2527c8fba92c65f40
-- 
gitgitgadget