Re: [PATCH v2 2/2] grep: use '/' delimiter for paths

Stefan Hajnoczi [off-list ref] writes:

Why check the equality with commit, rather than un-equality with
tree?  Wouldn't you want to treat $commit:path and $tag:path the
same way?

I also think the two patches should be squashed together, as it is
only after this patch that the code does the "right thing" by
changing the delimiter depending on obj->type.

Perhaps you want an annotated tag object refs/tags/v1.0 that points
at the commit at the HEAD, and then run the same grep on v1.0:t, in
addition to the above test.

 cat >expected <<EOF
 HEAD:t/a/v:vvv
 HEAD:t/v:vvv

On 01/20, Junio C Hamano wrote:

Stefan Hajnoczi [off-list ref] writes:

quoted

If the tree contains a sub-directory then git-grep(1) output contains a
colon character instead of a path separator:

  $ git grep malloc v2.9.3:t
  v2.9.3:t:test-lib.sh:	setup_malloc_check () {
  $ git show v2.9.3:t:test-lib.sh
  fatal: Path 't:test-lib.sh' does not exist in 'v2.9.3'

This patch attempts to use the correct delimiter:

  $ git grep malloc v2.9.3:t
  v2.9.3:t/test-lib.sh:	setup_malloc_check () {
  $ git show v2.9.3:t/test-lib.sh
  (success)

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 builtin/grep.c  | 4 +++-
 t/t7810-grep.sh | 5 +++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/builtin/grep.c b/builtin/grep.c
index 90a4f3d..7a7aab9 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c

@@ -494,7 +494,9 @@ static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 
 			/* Add a delimiter if there isn't one already */
 			if (name[len - 1] != '/' && name[len - 1] != ':') {
-				strbuf_addch(&base, ':');
+				/* rev: or rev:path/ */
+				char delim = obj->type == OBJ_COMMIT ? ':' : '/';

Why check the equality with commit, rather than un-equality with
tree?  Wouldn't you want to treat $commit:path and $tag:path the
same way?

I assume Stefan just grabbed my naive suggestion hence why it checks
equality with a commit.  So that's my fault :)  Either of these may
not be enough though, since if you do 'git grep malloc v2.9.3^{tree}'
with this change the output prefix is 'v2.9.3^{tree}/' instead of the
correct prefix 'v2.9.3^{tree}:'

I also think the two patches should be squashed together, as it is
only after this patch that the code does the "right thing" by
changing the delimiter depending on obj->type.

quoted

+				strbuf_addch(&base, delim);
 			}
 		}
 		init_tree_desc(&tree, data, size);

diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index e804a3f..8a58d5e 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh

@@ -1445,6 +1445,11 @@ test_expect_success 'grep outputs valid <rev>:<path> for HEAD:t/' '
 	test_cmp expected actual
 '
 
+test_expect_success 'grep outputs valid <rev>:<path> for HEAD:t' '
+	git grep vvv HEAD:t >actual &&
+	test_cmp expected actual
+'
+

Perhaps you want an annotated tag object refs/tags/v1.0 that points
at the commit at the HEAD, and then run the same grep on v1.0:t, in
addition to the above test.

quoted

 cat >expected <<EOF
 HEAD:t/a/v:vvv
 HEAD:t/v:vvv

-- 
Brandon Williams

On Fri, Jan 20, 2017 at 03:51:33PM -0800, Brandon Williams wrote:

On 01/20, Junio C Hamano wrote:

quoted

Stefan Hajnoczi [off-list ref] writes:

quoted

If the tree contains a sub-directory then git-grep(1) output contains a
colon character instead of a path separator:

  $ git grep malloc v2.9.3:t
  v2.9.3:t:test-lib.sh:	setup_malloc_check () {
  $ git show v2.9.3:t:test-lib.sh
  fatal: Path 't:test-lib.sh' does not exist in 'v2.9.3'

This patch attempts to use the correct delimiter:

  $ git grep malloc v2.9.3:t
  v2.9.3:t/test-lib.sh:	setup_malloc_check () {
  $ git show v2.9.3:t/test-lib.sh
  (success)

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 builtin/grep.c  | 4 +++-
 t/t7810-grep.sh | 5 +++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/builtin/grep.c b/builtin/grep.c
index 90a4f3d..7a7aab9 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c

@@ -494,7 +494,9 @@ static int grep_object(struct grep_opt *opt, const struct pathspec *pathspec,
 
 			/* Add a delimiter if there isn't one already */
 			if (name[len - 1] != '/' && name[len - 1] != ':') {
-				strbuf_addch(&base, ':');
+				/* rev: or rev:path/ */
+				char delim = obj->type == OBJ_COMMIT ? ':' : '/';

Why check the equality with commit, rather than un-equality with
tree?  Wouldn't you want to treat $commit:path and $tag:path the
same way?

I assume Stefan just grabbed my naive suggestion hence why it checks
equality with a commit.  So that's my fault :)  Either of these may
not be enough though, since if you do 'git grep malloc v2.9.3^{tree}'
with this change the output prefix is 'v2.9.3^{tree}/' instead of the
correct prefix 'v2.9.3^{tree}:'

I revisited this series again today and am coming to the conclusion that
forming output based on the user's rev is really hard to get right in
all cases.  I don't have a good solution to the v2.9.3^{tree} problem.

Perhaps it's better to leave this than to merge code that doesn't work
correctly 100% of the time.

Stefan

On Tue, Feb 07, 2017 at 03:04:14PM +0000, Stefan Hajnoczi wrote:

quoted

I assume Stefan just grabbed my naive suggestion hence why it checks
equality with a commit.  So that's my fault :)  Either of these may
not be enough though, since if you do 'git grep malloc v2.9.3^{tree}'
with this change the output prefix is 'v2.9.3^{tree}/' instead of the
correct prefix 'v2.9.3^{tree}:'

I revisited this series again today and am coming to the conclusion that
forming output based on the user's rev is really hard to get right in
all cases.  I don't have a good solution to the v2.9.3^{tree} problem.

I think the rule you need is not "are we at a tree", but rather "did we
traverse a path while resolving the name?". Only the get_sha1() parser
can tell you that. I think:

  char delim = ':';
  struct object_context oc;
  if (get_sha1_with_context(name, 0, sha1, &oc))
          die("...");
  if (oc.path[0])
          delim = '/'; /* name had a partial path */

would work. Root trees via "v2.9.3^{tree}" or "v2.9.3:" would have no
path, but "v2.9.3:Documentation" would. I think you'd still need to
avoid duplicating a trailing delimiter, but I can't think of a case
where it is wrong to do that based purely on the name.

-Peff