From: Jim Hill <gjthill@gmail.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org
Subject: [PATCH] sha1_file: pass empty buffer to index empty file
Date: Thu, 14 May 2015 10:23:39 -0700 [thread overview]
Message-ID: <1431624219-25045-1-git-send-email-gjthill@gmail.com> (raw)
`git add` of an empty file with a filter currently pops complaints from
`copy_fd` about a bad file descriptor.
This traces back to these lines in sha1_file.c:index_core:
if (!size) {
ret = index_mem(sha1, NULL, size, type, path, flags);
The problem here is that content to be added to the index can be
supplied from an fd, or from a memory buffer, or from a pathname. This
call is supplying a NULL buffer pointer and a zero size.
Downstream logic takes the complete absence of a buffer to mean the
data is to be found elsewhere -- for instance, these, from convert.c:
if (params->src) {
write_err = (write_in_full(child_process.in, params->src, params->size) < 0);
} else {
write_err = copy_fd(params->fd, child_process.in);
}
~If there's a buffer, write from that, otherwise the data must be coming
from an open fd.~
Perfectly reasonable logic in a routine that's going to write from
either a buffer or an fd.
So change `index_core` to supply an empty buffer when indexing an empty
file.
There's a patch out there that instead changes the logic quoted above to
take a `-1` fd to mean "use the buffer", but it seems to me that the
distinction between a missing buffer and an empty one carries intrinsic
semantics, where the logic change is adapting the code to handle
incorrect arguments.
Signed-off-by: Jim Hill <gjthill@gmail.com>
---
sha1_file.c | 2 +-
t/t2205-add-empty-filtered-file.sh | 21 +++++++++++++++++++++
2 files changed, 22 insertions(+), 1 deletion(-)
create mode 100755 t/t2205-add-empty-filtered-file.sh
diff --git a/sha1_file.c b/sha1_file.c
index f860d67..61e2735 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -3186,7 +3186,7 @@ static int index_core(unsigned char *sha1, int fd, size_t size,
int ret;
if (!size) {
- ret = index_mem(sha1, NULL, size, type, path, flags);
+ ret = index_mem(sha1, "", size, type, path, flags);
} else if (size <= SMALL_FILE_SIZE) {
char *buf = xmalloc(size);
if (size == read_in_full(fd, buf, size))
diff --git a/t/t2205-add-empty-filtered-file.sh b/t/t2205-add-empty-filtered-file.sh
new file mode 100755
index 0000000..28903c4
--- /dev/null
+++ b/t/t2205-add-empty-filtered-file.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+test_description='adding empty filtered file'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+ echo "* filter=test" >>.gitattributes &&
+ git config filter.test.clean cat &&
+ git config filter.test.smudge cat &&
+ git add . &&
+ git commit -m-
+
+'
+
+test_expect_success "add of empty filtered file produces no complaints" '
+ touch emptyfile &&
+ git add emptyfile 2>out &&
+ test -e out -a ! -s out
+'
+test_done
--
2.4.1.4.gd9c648d
next reply other threads:[~2015-05-14 17:23 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-14 17:23 Jim Hill [this message]
2015-05-14 18:43 ` [PATCH] sha1_file: pass empty buffer to index empty file Junio C Hamano
2015-05-14 23:17 ` [PATCH v2] " Jim Hill
2015-05-15 18:01 ` Junio C Hamano
2015-05-15 23:31 ` Jim Hill
2015-05-16 18:48 ` Junio C Hamano
2015-05-16 20:06 ` [PATCH v3] " Jim Hill
2015-05-16 23:22 ` Junio C Hamano
2015-05-17 17:37 ` Junio C Hamano
2015-05-17 19:10 ` Junio C Hamano
2015-05-18 0:41 ` [PATCH v4] " Jim Hill
2015-05-19 6:37 ` [PATCH v3] " Jeff King
2015-05-19 18:11 ` Junio C Hamano
2015-05-19 18:17 ` Junio C Hamano
2015-05-19 18:35 ` Junio C Hamano
2015-05-19 19:48 ` Junio C Hamano
2015-05-19 22:14 ` Jeff King
2015-05-20 17:03 ` Junio C Hamano
2015-05-19 19:40 ` Eric Sunshine
2015-05-19 22:09 ` Jeff King
2015-05-20 17:25 ` Junio C Hamano
2015-05-20 17:38 ` Jeff King
2015-05-14 23:26 ` [PATCH] " Jim Hill
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