rename read_replace_refs to check_replace_refs

The semantics of this flag was changed in commit

    e1111cef23 inline lookup_replace_object() calls

but wasn't renamed at the time to minimize code churn.  Rename it now,
and add a comment explaining its use.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/fsck.c

@@ -630,7 +630,7 @@ int cmd_fsck(int argc, const char **argv, const char *prefix)
 	struct alternate_object_database *alt;
 
 	errors_found = 0;
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 
 	argc = parse_options(argc, argv, prefix, fsck_opts, fsck_usage, 0);
 

builtin/index-pack.c

@@ -1502,7 +1502,7 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage(index_pack_usage);
 
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 
 	reset_pack_idx_option(&opts);
 	git_config(git_index_pack_config, &opts);

builtin/pack-objects.c

@@ -2507,7 +2507,7 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 		OPT_END(),
 	};
 
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 
 	reset_pack_idx_option(&pack_idx_opts);
 	git_config(git_pack_config, NULL);

builtin/prune.c

@@ -150,7 +150,7 @@ int cmd_prune(int argc, const char **argv, const char *prefix)
 
 	expire = ULONG_MAX;
 	save_commit_buffer = 0;
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 	init_revisions(&revs, prefix);
 
 	argc = parse_options(argc, argv, prefix, options, prune_usage, 0);

builtin/replace.c

@@ -178,7 +178,7 @@ int cmd_replace(int argc, const char **argv, const char *prefix)
 		OPT_END()
 	};
 
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 
 	argc = parse_options(argc, argv, prefix, options, git_replace_usage, 0);
 

builtin/unpack-objects.c

@@ -497,7 +497,7 @@ int cmd_unpack_objects(int argc, const char **argv, const char *prefix)
 	int i;
 	unsigned char sha1[20];
 
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 
 	git_config(git_default_config, NULL);
 

cache.h

@@ -580,7 +580,17 @@ extern size_t packed_git_limit;
 extern size_t delta_base_cache_limit;
 extern unsigned long big_file_threshold;
 extern unsigned long pack_size_limit_cfg;
-extern int read_replace_refs;
+
+/*
+ * Do replace refs need to be checked this run?  This variable is
+ * initialized to true unless --no-replace-object is used or
+ * $GIT_NO_REPLACE_OBJECTS is set, but is set to false by some
+ * commands that do not want replace references to be active.  As an
+ * optimization it is also set to false if replace references have
+ * been sought but there were none.
+ */
+extern int check_replace_refs;
+
 extern int fsync_object_files;
 extern int core_preload_index;
 extern int core_apply_sparse_checkout;
@@ -791,7 +801,7 @@ static inline void *read_sha1_file(const unsigned char *sha1, enum object_type *
 extern const unsigned char *do_lookup_replace_object(const unsigned char *sha1);
 static inline const unsigned char *lookup_replace_object(const unsigned char *sha1)
 {
-	if (!read_replace_refs)
+	if (!check_replace_refs)
 		return sha1;
 	return do_lookup_replace_object(sha1);
 }

environment.c

@@ -45,7 +45,7 @@ const char *editor_program;
 const char *askpass_program;
 const char *excludes_file;
 enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
-int read_replace_refs = 1; /* NEEDSWORK: rename to use_replace_refs */
+int check_replace_refs = 1;
 enum eol core_eol = EOL_UNSET;
 enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
@@ -147,7 +147,7 @@ static void setup_git_env(void)
 	if (!git_graft_file)
 		git_graft_file = git_pathdup("info/grafts");
 	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
-		read_replace_refs = 0;
+		check_replace_refs = 0;
 	namespace = expand_namespace(getenv(GIT_NAMESPACE_ENVIRONMENT));
 	namespace_len = strlen(namespace);
 	shallow_file = getenv(GIT_SHALLOW_FILE_ENVIRONMENT);

git.c

@@ -78,7 +78,7 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			if (envchanged)
 				*envchanged = 1;
 		} else if (!strcmp(cmd, "--no-replace-objects")) {
-			read_replace_refs = 0;
+			check_replace_refs = 0;
 			setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
 			if (envchanged)
 				*envchanged = 1;

log-tree.c

@@ -100,7 +100,7 @@ static int add_ref_decoration(const char *refname, const unsigned char *sha1, in
 
 	if (starts_with(refname, "refs/replace/")) {
 		unsigned char original_sha1[20];
-		if (!read_replace_refs)
+		if (!check_replace_refs)
 			return 0;
 		if (get_sha1_hex(refname + 13, original_sha1)) {
 			warning("invalid replace ref %s", refname);

replace_object.c

@@ -86,7 +86,7 @@ static void prepare_replace_object(void)
 	for_each_replace_ref(register_replace_ref, NULL);
 	replace_object_prepared = 1;
 	if (!replace_object_nr)
-		read_replace_refs = 0;
+		check_replace_refs = 0;
 }
 
 /* We allow "recursive" replacement. Only within reason, though */

upload-pack.c

@@ -796,7 +796,7 @@ int main(int argc, char **argv)
 
 	packet_trace_identity("upload-pack");
 	git_extract_argv0_path(argv[0]);
-	read_replace_refs = 0;
+	check_replace_refs = 0;
 
 	for (i = 1; i < argc; i++) {
 		char *arg = argv[i];