Filtering to support keyword expansion may need the name of
the file being filtered. In particular, to support p4 keywords
like
$File: //depot/product/dir/script.sh $
the smudge filter needs to know the name of the file it is
smudging.
Add a "%s" conversion specifier to the gitattribute for filter.
It will be expanded with the path name to the file when invoking
the external filter command.
Signed-off-by: Pete Wyckoff <pw@xxxxxxxx>
---
pw@xxxxxxxx wrote on Sat, 18 Dec 2010 17:38 -0500:
> I'm using git-p4 to import and work with upstream p4
> repositories. Some of the files are ktext, meaning they expect
> expansion of $Id$ and similar identifiers.
>
> Using the filter driver for this file, I can do the "clean" part
> easily, but to calculate the "smudge" correctly, I need to know
> the filename inside the filter driver.
This works fine for me. It is backward compatible, and leaves
open the possibility of adding other % modifiers if we find
a need later.
I have a filter that handles all the p4 $Keyword$ expansions,
now, using this patch. It can go into contrib if others would
find it useful. This seriously reduces many hassles associated
with my git-p4 workflow, where a plethora of ancillary systems
rely on keyword expansion in the source.
Cc Junio for comments as the original author of convert filter
code.
-- Pete
Documentation/gitattributes.txt | 12 ++++++++++++
convert.c | 15 ++++++++++++++-
2 files changed, 26 insertions(+), 1 deletions(-)
diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
index 564586b..9ac2138 100644
--- a/Documentation/gitattributes.txt
+++ b/Documentation/gitattributes.txt
@@ -317,6 +317,18 @@ command is "cat").
smudge = cat
------------------------
+If your filter needs the path of the file it is working on,
+you can use the "%s" conversion specification. It will be
+replaced with the relative path to the file. This is important
+for keyword substitution that depends on the name of the
+file. Like this:
+
+------------------------
+[filter "p4"]
+ clean = git-p4-filter --clean %s
+ smudge = git-p4-filter --smudge %s
+------------------------
+
Interaction between checkin/checkout attributes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/convert.c b/convert.c
index e41a31e..d4c6ed1 100644
--- a/convert.c
+++ b/convert.c
@@ -317,6 +317,7 @@ struct filter_params {
const char *src;
unsigned long size;
const char *cmd;
+ const char *path;
};
static int filter_buffer(int in, int out, void *data)
@@ -329,7 +330,16 @@ static int filter_buffer(int in, int out, void *data)
int write_err, status;
const char *argv[] = { NULL, NULL };
- argv[0] = params->cmd;
+ /* replace optional %s with path */
+ struct strbuf cmd = STRBUF_INIT;
+ struct strbuf_expand_dict_entry dict[] = {
+ "s", params->path,
+ NULL, NULL,
+ };
+
+ strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
+
+ argv[0] = cmd.buf;
memset(&child_process, 0, sizeof(child_process));
child_process.argv = argv;
@@ -349,6 +359,8 @@ static int filter_buffer(int in, int out, void *data)
status = finish_command(&child_process);
if (status)
error("external filter %s failed %d", params->cmd, status);
+
+ strbuf_release(&cmd);
return (write_err || status);
}
@@ -376,6 +388,7 @@ static int apply_filter(const char *path, const char *src, size_t len,
params.src = src;
params.size = len;
params.cmd = cmd;
+ params.path = path;
fflush(NULL);
if (start_async(&async))
--
1.7.2.3
--
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