diff-merges: introduce log.diffMerges config variable

sorganov · gitster · commit 17c13e60fd79 · 2021-04-16T23:38:35.000-07:00
New log.diffMerges configuration variable sets the format that
--diff-merges=on will be using. The default is "separate".

t4013: add the following tests for log.diffMerges config:

* Test that wrong values are denied.

* Test that the value of log.diffMerges properly affects both
--diff-merges=on and -m.

t9902: fix completion tests for log.d* to match log.diffMerges.

Added documentation for log.diffMerges.

Signed-off-by: Sergey Organov &lt;sorganov@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Documentation/config/log.txt b/Documentation/config/log.txt
@@ -24,6 +24,11 @@ log.excludeDecoration::
 	the config option can be overridden by the `--decorate-refs`
 	option.
 
+log.diffMerges::
+	Set default diff format to be used for merge commits. See
+	`--diff-merges` in linkgit:git-log[1] for details.
+	Defaults to `separate`.
+
 log.follow::
 	If `true`, `git log` will act as if the `--follow` option was used when
 	a single <path> is given.  This has the same limitations as `--follow`,
diff --git a/builtin/log.c b/builtin/log.c
@@ -481,6 +481,8 @@ static int git_log_config(const char *var, const char *value, void *cb)
 			decoration_style = 0; /* maybe warn? */
 		return 0;
 	}
+	if (!strcmp(var, "log.diffmerges"))
+		return diff_merges_config(value);
 	if (!strcmp(var, "log.showroot")) {
 		default_show_root = git_config_bool(var, value);
 		return 0;
diff --git a/diff-merges.c b/diff-merges.c
@@ -90,6 +90,17 @@ static void set_diff_merges(struct rev_info *revs, const char *optarg)
  * Public functions. They are in the order they are called.
  */
 
+int diff_merges_config(const char *value)
+{
+	diff_merges_setup_func_t func = func_by_opt(value);
+
+	if (!func)
+		return -1;
+
+	set_to_default = func;
+	return 0;
+}
+
 int diff_merges_parse_opts(struct rev_info *revs, const char **argv)
 {
 	int argcount = 1;
diff --git a/diff-merges.h b/diff-merges.h
@@ -9,6 +9,8 @@
 
 struct rev_info;
 
+int diff_merges_config(const char *value);
+
 int diff_merges_parse_opts(struct rev_info *revs, const char **argv);
 
 void diff_merges_suppress(struct rev_info *revs);
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
@@ -460,6 +460,29 @@ test_expect_success 'log --diff-merges=on matches --diff-merges=separate' '
 	test_cmp expected actual
 '
 
+test_expect_success 'deny wrong log.diffMerges config' '
+	test_config log.diffMerges wrong-value &&
+	test_expect_code 128 git log
+'
+
+test_expect_success 'git config log.diffMerges first-parent' '
+	git log -p --diff-merges=first-parent master >result &&
+	process_diffs result >expected &&
+	test_config log.diffMerges first-parent &&
+	git log -p --diff-merges=on master >result &&
+	process_diffs result >actual &&
+	test_cmp expected actual
+'
+
+test_expect_success 'git config log.diffMerges first-parent vs -m' '
+	git log -p --diff-merges=first-parent master >result &&
+	process_diffs result >expected &&
+	test_config log.diffMerges first-parent &&
+	git log -p -m master >result &&
+	process_diffs result >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'log -S requires an argument' '
 	test_must_fail git log -S
 '
diff --git a/t/t9902-completion.sh b/t/t9902-completion.sh
@@ -2306,6 +2306,7 @@ test_expect_success 'git config - variable name' '
 	test_completion "git config log.d" <<-\EOF
 	log.date Z
 	log.decorate Z
+	log.diffMerges Z
 	EOF
 '
 
@@ -2327,6 +2328,7 @@ test_expect_success 'git -c - variable name' '
 	test_completion "git -c log.d" <<-\EOF
 	log.date=Z
 	log.decorate=Z
+	log.diffMerges=Z
 	EOF
 '
 
@@ -2348,6 +2350,7 @@ test_expect_success 'git clone --config= - variable name' '
 	test_completion "git clone --config=log.d" <<-\EOF
 	log.date=Z
 	log.decorate=Z
+	log.diffMerges=Z
 	EOF
 '
 

Original file line number	Diff line number	Diff line change
`@@ -481,6 +481,8 @@ static int git_log_config(const char var, const char value, void *cb)`
`481`	`481`	`decoration_style = 0; /* maybe warn? */`
`482`	`482`	`return 0;`
`483`	`483`	`}`
	`484`	`+ if (!strcmp(var, "log.diffmerges"))`
	`485`	`+ return diff_merges_config(value);`
`484`	`486`	`if (!strcmp(var, "log.showroot")) {`
`485`	`487`	`default_show_root = git_config_bool(var, value);`
`486`	`488`	`return 0;`
Original file line number	Diff line number	Diff line change
`@@ -2306,6 +2306,7 @@ test_expect_success 'git config - variable name' '`
`2306`	`2306`	`test_completion "git config log.d" <<-\EOF`
`2307`	`2307`	`log.date Z`
`2308`	`2308`	`log.decorate Z`
	`2309`	`+ log.diffMerges Z`
`2309`	`2310`	`EOF`
`2310`	`2311`	`'`
`2311`	`2312`
`@@ -2327,6 +2328,7 @@ test_expect_success 'git -c - variable name' '`
`2327`	`2328`	`test_completion "git -c log.d" <<-\EOF`
`2328`	`2329`	`log.date=Z`
`2329`	`2330`	`log.decorate=Z`
	`2331`	`+ log.diffMerges=Z`
`2330`	`2332`	`EOF`
`2331`	`2333`	`'`
`2332`	`2334`
`@@ -2348,6 +2350,7 @@ test_expect_success 'git clone --config= - variable name' '`
`2348`	`2350`	`test_completion "git clone --config=log.d" <<-\EOF`
`2349`	`2351`	`log.date=Z`
`2350`	`2352`	`log.decorate=Z`
	`2353`	`+ log.diffMerges=Z`
`2351`	`2354`	`EOF`
`2352`	`2355`	`'`
`2353`	`2356`