Re: git: 590126789c84 - main - diff: Don't compare a file or directory to itself

Am Tage des Herren Thu, 05 Feb 2026 14:45:49 +0000
Dag-Erling Smørgrav <des@FreeBSD.org> schrieb:

> The branch main has been updated by des:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=590126789c841d80655869bc075c8980c173dd1c
> 
> commit 590126789c841d80655869bc075c8980c173dd1c
> Author:     Dag-Erling Smørgrav <des@FreeBSD.org>
> AuthorDate: 2026-02-05 14:39:57 +0000
> Commit:     Dag-Erling Smørgrav <des@FreeBSD.org>
> CommitDate: 2026-02-05 14:39:57 +0000
> 
>     diff: Don't compare a file or directory to itself
>     
>     While here, stop abusing struct dirent for something we don't even need
>     to store.
>     
>     PR:             254455
>     MFC after:      1 week
>     Sponsored by:   Klara, Inc.
>     Reviewed by:    thj, kevans
>     Differential Revision:  https://reviews.freebsd.org/D55113
> ---
>  usr.bin/diff/diffdir.c          | 14 ++++++--------
>  usr.bin/diff/diffreg.c          |  3 +++
>  usr.bin/diff/tests/diff_test.sh | 19 +++++++++++++++++++
>  3 files changed, 28 insertions(+), 8 deletions(-)
> 
> diff --git a/usr.bin/diff/diffdir.c b/usr.bin/diff/diffdir.c
> index a55a2bec70ee..bd8ef73e785a 100644
> --- a/usr.bin/diff/diffdir.c
> +++ b/usr.bin/diff/diffdir.c
> @@ -41,8 +41,6 @@ static void diffit(struct dirent *, char *, size_t, struct dirent *,
>  	char *, size_t, int);
>  static void print_only(const char *, size_t, const char *);
>  
> -#define d_status	d_type		/* we need to store status for -l */
> -
>  struct inode {
>  	dev_t dev;
>  	ino_t ino;
> @@ -258,7 +256,6 @@ diffit(struct dirent *dp, char *path1, size_t plen1, struct dirent *dp2,
>  			flags |= D_EMPTY1;
>  			memset(&stb1, 0, sizeof(stb1));
>  		}
> -
>  		if (lstat(path2, &stb2) != 0) {
>  			if (!Nflag || errno != ENOENT) {
>  				warn("%s", path2);
> @@ -315,7 +312,6 @@ diffit(struct dirent *dp, char *path1, size_t plen1, struct dirent *dp2,
>  			flags |= D_EMPTY1;
>  			memset(&stb1, 0, sizeof(stb1));
>  		}
> -
>  		if (stat(path2, &stb2) != 0) {
>  			if (!Nflag || errno != ENOENT) {
>  				warn("%s", path2);
> @@ -328,6 +324,8 @@ diffit(struct dirent *dp, char *path1, size_t plen1, struct dirent *dp2,
>  		if (stb1.st_mode == 0)
>  			stb1.st_mode = stb2.st_mode;
>  	}
> +	if (stb1.st_dev == stb2.st_dev && stb1.st_ino == stb2.st_ino)
> +		return;
>  	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
>  		if (rflag)
>  			diffdir(path1, path2, flags);
> @@ -337,12 +335,12 @@ diffit(struct dirent *dp, char *path1, size_t plen1, struct dirent
> *dp2, return;
>  	}
>  	if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
> -		dp->d_status = D_SKIPPED1;
> +		rc = D_SKIPPED1;
>  	else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
> -		dp->d_status = D_SKIPPED2;
> +		rc = D_SKIPPED2;
>  	else
> -		dp->d_status = diffreg(path1, path2, flags, 0);
> -	print_status(dp->d_status, path1, path2, "");
> +		rc = diffreg(path1, path2, flags, 0);
> +	print_status(rc, path1, path2, "");
>  }
>  
>  /*
> diff --git a/usr.bin/diff/diffreg.c b/usr.bin/diff/diffreg.c
> index 91ae5ee6591a..95c724817ede 100644
> --- a/usr.bin/diff/diffreg.c
> +++ b/usr.bin/diff/diffreg.c
> @@ -372,6 +372,9 @@ diffreg_stone(char *file1, char *file2, int flags, int capsicum)
>  		goto closem;
>  	}
>  
> +	if (stb1.st_dev == stb2.st_dev && stb1.st_ino == stb2.st_ino)
> +		goto closem;
> +
>  	if (lflag)
>  		pr = start_pr(file1, file2);
>  
> diff --git a/usr.bin/diff/tests/diff_test.sh b/usr.bin/diff/tests/diff_test.sh
> index a3f76602cf37..0c8147c7ed18 100755
> --- a/usr.bin/diff/tests/diff_test.sh
> +++ b/usr.bin/diff/tests/diff_test.sh
> @@ -432,6 +432,24 @@ prleak_body()
>  	atf_check diff -Astone -rul a b
>  }
>  
> +same_head()
> +{
> +	atf_set "descr" "Don't diff a file or directory with itself"
> +}
> +same_body()
> +{
> +	local n=256
> +	mkdir a
> +	for hi in $(jot -w%02x $n 0) ; do
> +		mkdir a/$hi
> +		for lo in $(jot -w%02x $n 0) ; do
> +			echo "$hi$lo" >a/$hi/$lo
> +		done
> +	done
> +	ln -s a b
> +	atf_check timeout 1s diff -rqs a b
> +}
> +
>  atf_init_test_cases()
>  {
>  	atf_add_test_case simple
> @@ -462,4 +480,5 @@ atf_init_test_cases()
>  	atf_add_test_case bigc
>  	atf_add_test_case bigu
>  	atf_add_test_case prleak
> +	atf_add_test_case same
>  }
> 
Buildworld seems to fail with newly added diff code:

[...]
--- all_subdir_usr.bin ---
  342 |                 rc = diffreg(path1, path2, flags, 0);
      |                 ^
/usr/src/usr.bin/diff/diffdir.c:343:15: error: use of undeclared identifier 'rc'
  343 |         print_status(rc, path1, path2, "");



Kind regards,

oh
-- 

A FreeBSD user