[PATCH 01/14] cmd_{read,write}_tree: rename "unused" variable that is used

[Jeff King <peff@peff.net>]

The "prefix" variable passed by git.c into the builtin cmd_read_tree()
and cmd_write_tree() functions is named "unused_prefix". But we do in
fact pass it to parse_options(), which may use the prefix to adjust any
filename options. Let's get rid of this confusing name.

However, we can't just call it "prefix". The reason these variables were
renamed in the first place is that they shadowed local variables named
"prefix", because these commands both take a "--prefix" option.

So let's rename the parameters, but try to reduce further confusion:

  1. In both cases we'll call them "cmd_prefix" to mark that they're
     part of the cmd_* interface.

  2. In cmd_write_tree(), we'll rename the local prefix variable to
     "tree_prefix" to make it more clear that we're talking about the
     prefix to be used for the tree we're writing.

  3. In cmd_read_tree(), the "prefix" local has since migrated into
     "struct unpack_trees_options". We'll leave that alone, as the
     context within the struct makes its meaning clear (we actually
     _could_ just call the parameter "prefix" now, but that invites
     confusion in the other direction).

Signed-off-by: Jeff King <peff@peff.net>
---
I kind of hate "cmd_prefix"; I was tempted to just call it "prefix" so
that all of the cmd_* functions were consistent, but I worried that it
really would get confused with the local variables (even if those
variables are renamed, as I do here).

 builtin/read-tree.c  |  4 ++--
 builtin/write-tree.c | 12 ++++++------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 5c9c082595..ca5e655d2f 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -111,7 +111,7 @@ static int git_read_tree_config(const char *var, const char *value, void *cb)
 	return git_default_config(var, value, cb);
 }
 
-int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
+int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 {
 	int i, stage = 0;
 	struct object_id oid;
@@ -165,7 +165,7 @@ int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
 
 	git_config(git_read_tree_config, NULL);
 
-	argc = parse_options(argc, argv, unused_prefix, read_tree_options,
+	argc = parse_options(argc, argv, cmd_prefix, read_tree_options,
 			     read_tree_usage, 0);
 
 	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
diff --git a/builtin/write-tree.c b/builtin/write-tree.c
index 3d46d22ee5..45d61707e7 100644
--- a/builtin/write-tree.c
+++ b/builtin/write-tree.c
@@ -16,16 +16,16 @@ static const char * const write_tree_usage[] = {
 	NULL
 };
 
-int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
+int cmd_write_tree(int argc, const char **argv, const char *cmd_prefix)
 {
 	int flags = 0, ret;
-	const char *prefix = NULL;
+	const char *tree_prefix = NULL;
 	struct object_id oid;
 	const char *me = "git-write-tree";
 	struct option write_tree_options[] = {
 		OPT_BIT(0, "missing-ok", &flags, N_("allow missing objects"),
 			WRITE_TREE_MISSING_OK),
-		OPT_STRING(0, "prefix", &prefix, N_("<prefix>/"),
+		OPT_STRING(0, "prefix", &tree_prefix, N_("<prefix>/"),
 			   N_("write tree object for a subdirectory <prefix>")),
 		{ OPTION_BIT, 0, "ignore-cache-tree", &flags, NULL,
 		  N_("only useful for debugging"),
@@ -35,10 +35,10 @@ int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
 	};
 
 	git_config(git_default_config, NULL);
-	argc = parse_options(argc, argv, unused_prefix, write_tree_options,
+	argc = parse_options(argc, argv, cmd_prefix, write_tree_options,
 			     write_tree_usage, 0);
 
-	ret = write_cache_as_tree(&oid, flags, prefix);
+	ret = write_cache_as_tree(&oid, flags, tree_prefix);
 	switch (ret) {
 	case 0:
 		printf("%s\n", oid_to_hex(&oid));
@@ -50,7 +50,7 @@ int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
 		die("%s: error building trees", me);
 		break;
 	case WRITE_TREE_PREFIX_ERROR:
-		die("%s: prefix %s not found", me, prefix);
+		die("%s: prefix %s not found", me, tree_prefix);
 		break;
 	}
 	return ret;
-- 
2.21.0.1382.g4c6032d436