log and diff family: honor config even from subdirectories

There currently is an unfortunate circular dependency between
what init_revisions (the command line revision specification
parser) does and setting up the log and diff options.  The
function uses setup_git_directory() to find the root of the
project relative to the current directory and calls diff_setup()
to prepare diff generation.  However, some of the things that
diff_setup() does needs to depend on the configuration variable,
which needs to be read after setup_git_directory() is called.

This patch is a low impact workaround.  It first lets
init_revisions() to run and do its thing, then uses git_config()
and diff_setup() after it returns, so that configuration
variables that affects the diff operation can be used from
subdirectories.

Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-diff-files.c

@@ -18,8 +18,8 @@ int cmd_diff_files(int argc, const char **argv, char **envp)
 	struct rev_info rev;
 	int silent = 0;
 
-	git_config(git_default_config); /* no "diff" UI options */
 	init_revisions(&rev);
+	git_config(git_default_config); /* no "diff" UI options */
 	rev.abbrev = 0;
 
 	argc = setup_revisions(argc, argv, &rev, NULL);

builtin-diff-index.c

@@ -15,8 +15,8 @@ int cmd_diff_index(int argc, const char **argv, char **envp)
 	int cached = 0;
 	int i;
 
-	git_config(git_default_config); /* no "diff" UI options */
 	init_revisions(&rev);
+	git_config(git_default_config); /* no "diff" UI options */
 	rev.abbrev = 0;
 
 	argc = setup_revisions(argc, argv, &rev, NULL);

builtin-diff-tree.c

@@ -67,9 +67,9 @@ int cmd_diff_tree(int argc, const char **argv, char **envp)
 	static struct rev_info *opt = &log_tree_opt;
 	int read_stdin = 0;
 
+	init_revisions(opt);
 	git_config(git_default_config); /* no "diff" UI options */
 	nr_sha1 = 0;
-	init_revisions(opt);
 	opt->abbrev = 0;
 	opt->diff = 1;
 	argc = setup_revisions(argc, argv, opt, NULL);

builtin-diff.c

@@ -250,8 +250,9 @@ int cmd_diff(int argc, const char **argv, char **envp)
 	 * Other cases are errors.
 	 */
 
-	git_config(git_diff_ui_config);
 	init_revisions(&rev);
+	git_config(git_diff_ui_config);
+	diff_setup(&rev.diffopt);
 
 	argc = setup_revisions(argc, argv, &rev, NULL);
 	if (!rev.diffopt.output_format) {

builtin-log.c

@@ -49,8 +49,9 @@ int cmd_whatchanged(int argc, const char **argv, char **envp)
 {
 	struct rev_info rev;
 
-	git_config(git_diff_ui_config);
 	init_revisions(&rev);
+	git_config(git_diff_ui_config);
+	diff_setup(&rev.diffopt);
 	rev.diff = 1;
 	rev.diffopt.recursive = 1;
 	rev.simplify_history = 0;
@@ -64,8 +65,9 @@ int cmd_show(int argc, const char **argv, char **envp)
 {
 	struct rev_info rev;
 
-	git_config(git_diff_ui_config);
 	init_revisions(&rev);
+	git_config(git_diff_ui_config);
+	diff_setup(&rev.diffopt);
 	rev.diff = 1;
 	rev.diffopt.recursive = 1;
 	rev.combine_merges = 1;
@@ -81,8 +83,9 @@ int cmd_log(int argc, const char **argv, char **envp)
 {
 	struct rev_info rev;
 
-	git_config(git_diff_ui_config);
 	init_revisions(&rev);
+	git_config(git_diff_ui_config);
+	diff_setup(&rev.diffopt);
 	rev.always_show_header = 1;
 	cmd_log_init(argc, argv, envp, &rev);
 	return cmd_log_walk(&rev);