[GSOC PATCH 1/2] environment: remove the global variable 'merge_log_config'

[Ayush Chandekar <ayu.chandekar@gmail.com>]

The global variable 'merge_log_config', set via the "merge.log" or
"merge.summary" settings, is only used in 'cmd_fmt_merge_msg()' and
'cmd_merge()' to adjust the 'shortlog_len' variable.

Remove 'merge_log_config' and introduce a function
'adjust_shortlog_len()' in fmt-merge-msg.c to handle the 'shortlog_len'
variable.

This change is part of an ongoing effort to eliminate global variables,
improve modularity and help libify the codebase.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Ghanshyam Thakkar <shyamthakkar001@gmail.com>
Signed-off-by: Ayush Chandekar <ayu.chandekar@gmail.com>
---
 builtin/fmt-merge-msg.c |  4 ++--
 builtin/merge.c         |  4 ++--
 environment.c           |  2 --
 fmt-merge-msg.c         | 30 ++++++++++++++++++++++--------
 fmt-merge-msg.h         |  3 ++-
 5 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 3b6aac2cf7..fed8163825 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -58,8 +58,8 @@ int cmd_fmt_merge_msg(int argc,
 			     0);
 	if (argc > 0)
 		usage_with_options(fmt_merge_msg_usage, options);
-	if (shortlog_len < 0)
-		shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
+
+	adjust_shortlog_len(the_repository, &shortlog_len);
 
 	if (inpath && strcmp(inpath, "-")) {
 		in = fopen(inpath, "r");
diff --git a/builtin/merge.c b/builtin/merge.c
index 18b22c0a26..e1cf2a6d63 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -1403,8 +1403,8 @@ int cmd_merge(int argc,
 		parse_branch_merge_options(branch_mergeoptions);
 	argc = parse_options(argc, argv, prefix, builtin_merge_options,
 			builtin_merge_usage, 0);
-	if (shortlog_len < 0)
-		shortlog_len = (merge_log_config > 0) ? merge_log_config : 0;
+
+	adjust_shortlog_len(the_repository, &shortlog_len);
 
 	if (verbosity < 0 && show_progress == -1)
 		show_progress = 0;
diff --git a/environment.c b/environment.c
index 7c2480b22e..74c9838b31 100644
--- a/environment.c
+++ b/environment.c
@@ -20,7 +20,6 @@
 #include "repository.h"
 #include "config.h"
 #include "refs.h"
-#include "fmt-merge-msg.h"
 #include "commit.h"
 #include "strvec.h"
 #include "path.h"
@@ -66,7 +65,6 @@ int grafts_keep_true_parents;
 int core_apply_sparse_checkout;
 int core_sparse_checkout_cone;
 int sparse_expect_files_outside_of_patterns;
-int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
 unsigned long pack_size_limit_cfg;
 int max_allowed_tree_depth =
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index 40174efa3d..2ceaebb0ce 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -26,14 +26,7 @@ static struct string_list suppress_dest_patterns = STRING_LIST_INIT_DUP;
 int fmt_merge_msg_config(const char *key, const char *value,
 			 const struct config_context *ctx, void *cb)
 {
-	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
-		int is_bool;
-		merge_log_config = git_config_bool_or_int(key, value, ctx->kvi, &is_bool);
-		if (!is_bool && merge_log_config < 0)
-			return error("%s: negative length %s", key, value);
-		if (is_bool && merge_log_config)
-			merge_log_config = DEFAULT_MERGE_LOG_LEN;
-	} else if (!strcmp(key, "merge.branchdesc")) {
+	if (!strcmp(key, "merge.branchdesc")) {
 		use_branch_desc = git_config_bool(key, value);
 	} else if (!strcmp(key, "merge.suppressdest")) {
 		if (!value)
@@ -645,6 +638,27 @@ static void find_merge_parents(struct merge_parents *result,
 	result->nr = j;
 }
 
+void adjust_shortlog_len(struct repository *r, int *shortlog_len)
+{
+	const char *keys[] = { "merge.log", "merge.summary", NULL};
+	
+	if (*shortlog_len >= 0)
+		return;
+
+	for (const char **key = keys; *key; ++key) {
+		int is_bool, value;
+		if (!repo_config_get_bool_or_int(r, *key, &is_bool, &value)) {
+			if (!is_bool && value < 0) {
+				error("%s: negative length %d", *key, value);
+				return;
+			}
+			*shortlog_len = (is_bool && value) ? DEFAULT_MERGE_LOG_LEN : value;
+			return;
+		}
+	}
+
+	*shortlog_len = 0;
+}
 
 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 		  struct fmt_merge_msg_opts *opts)
diff --git a/fmt-merge-msg.h b/fmt-merge-msg.h
index 73ca3e4465..f54f00d26f 100644
--- a/fmt-merge-msg.h
+++ b/fmt-merge-msg.h
@@ -2,6 +2,7 @@
 #define FMT_MERGE_MSG_H
 
 #include "strbuf.h"
+#include "repository.h"
 
 #define DEFAULT_MERGE_LOG_LEN 20
 
@@ -12,9 +13,9 @@ struct fmt_merge_msg_opts {
 	const char *into_name;
 };
 
-extern int merge_log_config;
 int fmt_merge_msg_config(const char *key, const char *value,
 			 const struct config_context *ctx, void *cb);
+void adjust_shortlog_len(struct repository *r, int *shortlog_len);
 int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 		  struct fmt_merge_msg_opts *);
 
-- 
2.49.0