Maybe we should not have a public constant defined for the length :
+#define LOCK_SUFFIX_LEN 5
since it encourages unsafe code like : (this was unsafe long before
your patch so not a regression)
+ i = strlen(result_file) - LOCK_SUFFIX_LEN; /* .lock */
result_file[i] = 0;
What about removing LOCK_SUFFIX_LEN from the public API and introduce
a helper function something like :
/* pointer to the character where the lock suffix starts */
char *lock_suffix_ptr_safe(const char *filename)
{
size_t len = strlen(filename);
if (len < 5)
die("BUG:...
if (strcmp(filename + len - 5, LOCK_SUFFIX)
die("BUG:...
return filename + len - 5;
}
and use it instead?
On Sat, Sep 6, 2014 at 12:50 AM, Michael Haggerty <mhag...@alum.mit.edu> wrote:
> There are a few places that use these values, so define constants for
> them.
>
> Signed-off-by: Michael Haggerty <mhag...@alum.mit.edu>
> ---
> cache.h | 4 ++++
> lockfile.c | 11 ++++++-----
> refs.c | 7 ++++---
> 3 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/cache.h b/cache.h
> index da77094..41d829b 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -569,6 +569,10 @@ extern void fill_stat_cache_info(struct cache_entry *ce,
> struct stat *st);
> #define REFRESH_IN_PORCELAIN 0x0020 /* user friendly output, not "needs
> update" */
> extern int refresh_index(struct index_state *, unsigned int flags, const
> struct pathspec *pathspec, char *seen, const char *header_msg);
>
> +/* String appended to a filename to derive the lockfile name: */
> +#define LOCK_SUFFIX ".lock"
> +#define LOCK_SUFFIX_LEN 5
> +
> struct lock_file {
> struct lock_file *next;
> int fd;
> diff --git a/lockfile.c b/lockfile.c
> index 964b3fc..bfea333 100644
> --- a/lockfile.c
> +++ b/lockfile.c
> @@ -176,10 +176,11 @@ static char *resolve_symlink(char *p, size_t s)
> static int lock_file(struct lock_file *lk, const char *path, int flags)
> {
> /*
> - * subtract 5 from size to make sure there's room for adding
> - * ".lock" for the lock file name
> + * subtract LOCK_SUFFIX_LEN from size to make sure there's
> + * room for adding ".lock" for the lock file name:
> */
> - static const size_t max_path_len = sizeof(lk->filename) - 5;
> + static const size_t max_path_len = sizeof(lk->filename) -
> + LOCK_SUFFIX_LEN;
>
> if (!lock_file_list) {
> /* One-time initialization */
> @@ -204,7 +205,7 @@ static int lock_file(struct lock_file *lk, const char
> *path, int flags)
> strcpy(lk->filename, path);
> if (!(flags & LOCK_NODEREF))
> resolve_symlink(lk->filename, max_path_len);
> - strcat(lk->filename, ".lock");
> + strcat(lk->filename, LOCK_SUFFIX);
> lk->fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666);
> if (0 <= lk->fd) {
> lk->owner = getpid();
> @@ -314,7 +315,7 @@ int commit_lock_file(struct lock_file *lk)
> if (lk->fd >= 0 && close_lock_file(lk))
> return -1;
> strcpy(result_file, lk->filename);
> - i = strlen(result_file) - 5; /* .lock */
> + i = strlen(result_file) - LOCK_SUFFIX_LEN; /* .lock */
> result_file[i] = 0;
> if (rename(lk->filename, result_file))
> return -1;
> diff --git a/refs.c b/refs.c
> index 5ae8e69..828522d 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -74,7 +74,8 @@ out:
> if (refname[1] == '\0')
> return -1; /* Component equals ".". */
> }
> - if (cp - refname >= 5 && !memcmp(cp - 5, ".lock", 5))
> + if (cp - refname >= LOCK_SUFFIX_LEN &&
> + !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
> return -1; /* Refname ends with ".lock". */
> return cp - refname;
> }
> @@ -2545,11 +2546,11 @@ static int delete_ref_loose(struct ref_lock *lock,
> int flag)
> {
> if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
> /* loose */
> - int err, i = strlen(lock->lk->filename) - 5; /* .lock */
> + int err, i = strlen(lock->lk->filename) - LOCK_SUFFIX_LEN;
>
> lock->lk->filename[i] = 0;
> err = unlink_or_warn(lock->lk->filename);
> - lock->lk->filename[i] = '.';
> + lock->lk->filename[i] = LOCK_SUFFIX[0];
> if (err && errno != ENOENT)
> return 1;
> }
> --
> 2.1.0
>
> --
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