patchname-hash: properly fold directory names in adjust_dirname_case()

Correct the pointer arithmetic in adjust_dirname_case() so that it calls find_dir_entry() with the correct string length. Previously passing in "dir1/foo" would pass a length of 6 instead of the correct 4. This resulted in find_dir_entry() never finding the entry and so the subsequent memcpy that would fold the name to the version with the correct case never executed.

Add a test to validate the corrected behavior with name folding of directories.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
---

Notes:
    Base Ref: v2.16.1
    Web-Diff: https://github.com/benpeart/git/commit/2944970f4e
    Checkout: git fetch https://github.com/benpeart/git adjust_dirname-v1 && git checkout 2944970f4e

 name-hash.c           |  6 +++---
 t/t0050-filesystem.sh | 12 +++++++++++-
 2 files changed, 14 insertions(+), 4 deletions(-)

On Wed, 2018-02-07 at 19:41 -0500, Ben Peart wrote:

Looks good to me.

On Wed, Feb 07, 2018 at 07:41:56PM -0500, Ben Peart wrote: []

There is nothing wrong with with "wc -l", but: a more new-style would probably use test_line_count() here.

My personal favorite would be to spell out what we expect and run a diff. When it fails, we can see what fails, and the function would look like this:

test_expect_success CASE_INSENSITIVE_FS 'add directory (with different case)' '
	git reset --hard initial &&
	mkdir -p dir1 &&
	mkdir -p dir1/dir2 &&
	touch dir1/dir2/a &&
	touch dir1/dir2/b &&
	git add dir1/dir2/a &&
	git add dir1/DIR2/b &&
	git ls-files | grep dir2 | sort >actual &&
	cat >expected <<-\EOF &&
	dir1/dir2/a
	dir1/dir2/b
	EOF
	test_cmp expected actual
'

On 2/8/2018 12:21 PM, Torsten Bögershausen wrote:

I agree with you completely that this is a better format and is easier to read. All the new tests I've been writing follow this same pattern.

In this particular test file, I opted (for better and for worse) to stick with the style of all the other tests rather than 1) have this one test be very different than all the others or 2) rewriting all the existing tests in the new style.

Torsten Bögershausen <tboegi@web.de> writes:

I'd rather not to have the "sort" there; output from ls-files is meant to be stable; passing it through sort would miss breakages. I agree that comparison between "expect" and "actual" is a good idea nevertheless.

Speaking of styles, I'd prefer to reserve use of "touch" to cases where resulting timestamp matters, and not "make sure it exists".

Thanks.

Ben Peart <benpeart@microsoft.com> writes:

Thanks.

It appears that this codepath has been miscounting ever since it was introduced in 41284eb0 ("name-hash: don't reuse cache_entry in dir_entry", 2015-10-21).

A single "mkdir -p dir1/dir2" should be sufficient, thanks to "-p" ;-)

Hmph.

Correct the pointer arithmetic in adjust_dirname_case() so that it calls find_dir_entry() with the correct string length. Previously passing in "dir1/foo" would pass a length of 6 instead of the correct 4. This resulted in find_dir_entry() never finding the entry and so the subsequent memcpy that would fold the name to the version with the correct case never executed.

Add a test to validate the corrected behavior with name folding of directories.

Signed-off-by: Ben Peart <benpeart@microsoft.com>
---

Notes:
    Base Ref: v2.16.1
    Web-Diff: https://github.com/benpeart/git/commit/477da4602c
    Checkout: git fetch https://github.com/benpeart/git adjust_dirname-v2 && git checkout 477da4602c
    
    ### Interdiff (v1..v2):
    
    diff --git a/t/t0050-filesystem.sh b/t/t0050-filesystem.sh
    index 219c96594c..0e4e51b79a 100755
    --- a/t/t0050-filesystem.sh
    +++ b/t/t0050-filesystem.sh
    @@ -82,14 +82,18 @@ test_expect_success 'merge (case change)' '
    
     test_expect_success CASE_INSENSITIVE_FS 'add directory (with different case)' '
     	git reset --hard initial &&
    -	mkdir -p dir1 &&
     	mkdir -p dir1/dir2 &&
    -	touch dir1/dir2/a &&
    -	touch dir1/dir2/b &&
    +	echo > dir1/dir2/a &&
    +	echo > dir1/dir2/b &&
     	git add dir1/dir2/a &&
     	git add dir1/DIR2/b &&
    -	camel=$(git ls-files | grep dir2) &&
    -	test $(echo "$camel" | wc -l) = 2
    +	git ls-files >actual &&
    +	cat >expected <<-\EOF &&
    +		camelcase
    +		dir1/dir2/a
    +		dir1/dir2/b
    +	EOF
    +	test_cmp expected actual
     '
    
     test_expect_failure CASE_INSENSITIVE_FS 'add (with different case)' '
    
    ### Patches

 name-hash.c           |  6 +++---
 t/t0050-filesystem.sh | 16 +++++++++++++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

On Thu, Feb 08, 2018 at 02:23:33PM -0500, Ben Peart wrote:

[]

Thanks for working on this-
One and a half style nits:
The ">" should be close to the file name:
	echo >dir1/dir2/a &&
But then we don't even look into the file, so that the "\" produced by echo is not needed.
A simple 
	>dir1/dir2/a &&
is all that is needed.