Re: [PATCH 4/4] core.abbrev: raise the default abbreviation to 12 hexdigits

[Junio C Hamano <gitster@pobox.com>]

Junio C Hamano <gitster@pobox.com> writes:

> There still are breakages seen in t5510 and t5526 that are about the
> verbose output of "git fetch".  I'll stop digging at this point
> tonight, and welcome others who look into it ;-)

OK, just before I leave the keyboard for the night...

-- >8 --
From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 29 Sep 2016 21:19:20 -0700
Subject: [PATCH] abbrev: adjust to the new world order

The default_abbrev used to be a concrete value usable as the default
abbreviation length.  The code that sets custom abbreviation length,
in response to command line argument, often did something like:

	if (skip_prefix(arg, "--abbrev=", &arg))
		abbrev = atoi(arg);
	else if (!strcmp("--abbrev", &arg))
		abbrev = DEFAULT_ABBREV;
	/* make the value sane */
	if (abbrev < 0 || 40 < abbrev)
		abbrev = ... some sane value ...

The new world order however is that the default_abbrev is a negative
value that signals find_unique_abbrev() that it needs to dynamically
find out a good default value.  We shouldn't coerce a negative value
into a random positive value like the above sample code.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/rev-parse.c | 5 +++--
 diff.c              | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/builtin/rev-parse.c b/builtin/rev-parse.c
index 76cf05e2ad..17cbfabdde 100644
--- a/builtin/rev-parse.c
+++ b/builtin/rev-parse.c
@@ -643,8 +643,9 @@ int cmd_rev_parse(int argc, const char **argv, const char *prefix)
 				filter &= ~(DO_FLAGS|DO_NOREV);
 				verify = 1;
 				abbrev = DEFAULT_ABBREV;
-				if (arg[7] == '=')
-					abbrev = strtoul(arg + 8, NULL, 10);
+				if (!arg[7])
+					continue;
+				abbrev = strtoul(arg + 8, NULL, 10);
 				if (abbrev < MINIMUM_ABBREV)
 					abbrev = MINIMUM_ABBREV;
 				else if (40 <= abbrev)
diff --git a/diff.c b/diff.c
index c6da383c56..cefc13eb8e 100644
--- a/diff.c
+++ b/diff.c
@@ -3399,7 +3399,7 @@ void diff_setup_done(struct diff_options *options)
 			 */
 			read_cache();
 	}
-	if (options->abbrev <= 0 || 40 < options->abbrev)
+	if (40 < options->abbrev)
 		options->abbrev = 40; /* full */
 
 	/*
-- 
2.10.0-612-g22341905f2