[PATCH 2/4] cat-file: split batch "buf" into two variables

[Jeff King]

We use the "buf" strbuf for two things: to read incoming
lines, and as a scratch space for test-expanding the
user-provided format. Let's split this into two variables
with descriptive names, which makes their purpose and
lifetime more clear.

It will also help in a future patch when we start using the
"output" buffer for more expansions.

Signed-off-by: Jeff King <p...@peff.net>
---
René, in the patch you sent earlier, I noticed that for the
non-batch-all-objects case we use the same strbuf for input and output.
That'd probably be OK most of the time (the first thing we do is resolve
the input to an oid), but I suspect it could be pretty bad with %(rest).
We'd write over or even realloc the string it points into as part of the
output.

This patch just clarifies the names; your reuse idea is in the next one.

 builtin/cat-file.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 04b5cda191..3ed1d0be80 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -466,7 +466,8 @@ static int batch_unordered_packed(const struct object_id 
*oid,
 
 static int batch_objects(struct batch_options *opt)
 {
-       struct strbuf buf = STRBUF_INIT;
+       struct strbuf input = STRBUF_INIT;
+       struct strbuf output = STRBUF_INIT;
        struct expand_data data;
        int save_warning;
        int retval = 0;
@@ -481,8 +482,9 @@ static int batch_objects(struct batch_options *opt)
         */
        memset(&data, 0, sizeof(data));
        data.mark_query = 1;
-       strbuf_expand(&buf, opt->format, expand_format, &data);
+       strbuf_expand(&output, opt->format, expand_format, &data);
        data.mark_query = 0;
+       strbuf_release(&output);
        if (opt->cmdmode)
                data.split_on_whitespace = 1;
 
@@ -542,14 +544,14 @@ static int batch_objects(struct batch_options *opt)
        save_warning = warn_on_object_refname_ambiguity;
        warn_on_object_refname_ambiguity = 0;
 
-       while (strbuf_getline(&buf, stdin) != EOF) {
+       while (strbuf_getline(&input, stdin) != EOF) {
                if (data.split_on_whitespace) {
                        /*
                         * Split at first whitespace, tying off the beginning
                         * of the string and saving the remainder (or NULL) in
                         * data.rest.
                         */
-                       char *p = strpbrk(buf.buf, " \t");
+                       char *p = strpbrk(input.buf, " \t");
                        if (p) {
                                while (*p && strchr(" \t", *p))
                                        *p++ = '\0';
@@ -557,10 +559,10 @@ static int batch_objects(struct batch_options *opt)
                        data.rest = p;
                }
 
-               batch_one_object(buf.buf, opt, &data);
+               batch_one_object(input.buf, opt, &data);
        }
 
-       strbuf_release(&buf);
+       strbuf_release(&input);
        warn_on_object_refname_ambiguity = save_warning;
        return retval;
 }
-- 
2.18.0.1066.g0d97f3a098