Add mailmap.file as configurational option for mailmap location

This allows us to augment the repo mailmap file, and to use
mailmap files elsewhere than the repository root. Meaning
that the entries in mailmap.file will override the entries
in "./.mailmap", should they match.

Signed-off-by: Marius Storm-Olsen <marius@trolltech.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -1012,6 +1012,14 @@ log.showroot::
 	Tools like linkgit:git-log[1] or linkgit:git-whatchanged[1], which
 	normally hide the root commit will now show it. True by default.
 
+mailmap.file::
+	The location of an augmenting mailmap file. The default
+	mailmap, located in the root of the repository, is loaded
+	first, then the mailmap file pointed to by this variable.
+	The location of the mailmap file may be in a repository
+	subdirectory, or somewhere outside of the repository itself.
+	See linkgit:git-shortlog[1] and linkgit:git-blame[1].
+
 man.viewer::
 	Specify the programs that may be used to display help in the
 	'man' format. See linkgit:git-help[1].

Documentation/git-shortlog.txt

@@ -48,7 +48,8 @@ OPTIONS
 FILES
 -----
 
-If a file `.mailmap` exists at the toplevel of the repository,
+If a file `.mailmap` exists at the toplevel of the repository, or at the
+location pointed to by the log.mailmap configuration option,
 it is used to map an author email address to a canonical real name. This
 can be used to coalesce together commits by the same person where their
 name was spelled differently (whether with the same email address or

builtin-blame.c

@@ -2394,7 +2394,7 @@ parse_done:
 		die("reading graft file %s failed: %s",
 		    revs_file, strerror(errno));
 
-	read_mailmap(&mailmap, ".mailmap", NULL);
+	read_mailmap(&mailmap, NULL);
 
 	if (!incremental)
 		setup_pager();

builtin-shortlog.c

@@ -219,7 +219,7 @@ void shortlog_init(struct shortlog *log)
 {
 	memset(log, 0, sizeof(*log));
 
-	read_mailmap(&log->mailmap, ".mailmap", &log->common_repo_prefix);
+	read_mailmap(&log->mailmap, &log->common_repo_prefix);
 
 	log->list.strdup_strings = 1;
 	log->wrap = DEFAULT_WRAPLEN;
@@ -248,6 +248,7 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 	struct parse_opt_ctx_t ctx;
 
 	prefix = setup_git_directory_gently(&nongit);
+	git_config(git_default_config, NULL);
 	shortlog_init(&log);
 	init_revisions(&rev, prefix);
 	parse_options_start(&ctx, argc, argv, PARSE_OPT_KEEP_DASHDASH |

cache.h

@@ -867,6 +867,7 @@ extern int user_ident_explicitly_given;
 
 extern const char *git_commit_encoding;
 extern const char *git_log_output_encoding;
+extern const char *git_mailmap_file;
 
 /* IO helper functions */
 extern void maybe_flush_or_die(FILE *, const char *);

config.c

@@ -565,6 +565,15 @@ static int git_default_branch_config(const char *var, const char *value)
 	return 0;
 }
 
+static int git_default_mailmap_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "mailmap.file"))
+		return git_config_string(&git_mailmap_file, var, value);
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
 int git_default_config(const char *var, const char *value, void *dummy)
 {
 	if (!prefixcmp(var, "core."))
@@ -579,6 +588,9 @@ int git_default_config(const char *var, const char *value, void *dummy)
 	if (!prefixcmp(var, "branch."))
 		return git_default_branch_config(var, value);
 
+	if (!prefixcmp(var, "mailmap."))
+		return git_default_mailmap_config(var, value);
+
 	if (!strcmp(var, "pager.color") || !strcmp(var, "color.pager")) {
 		pager_use_color = git_config_bool(var,value);
 		return 0;

mailmap.c

@@ -2,10 +2,11 @@
 #include "string-list.h"
 #include "mailmap.h"
 
-int read_mailmap(struct string_list *map, const char *filename, char **repo_abbrev)
+const char *git_mailmap_file;
+static int read_single_mailmap(struct string_list *map, const char *filename, char **repo_abbrev)
 {
 	char buffer[1024];
-	FILE *f = fopen(filename, "r");
+	FILE *f = (filename == NULL ? NULL : fopen(filename, "r"));
 
 	if (f == NULL)
 		return 1;
@@ -60,6 +61,13 @@ int read_mailmap(struct string_list *map, const char *filename, char **repo_abbr
 	return 0;
 }
 
+int read_mailmap(struct string_list *map, char **repo_abbrev)
+{
+	/* each failure returns 1, so >1 means both calls failed */
+	return read_single_mailmap(map, ".mailmap", repo_abbrev) +
+	       read_single_mailmap(map, git_mailmap_file, repo_abbrev) > 1;
+}
+
 int map_email(struct string_list *map, const char *email, char *name, int maxlen)
 {
 	char *p;

mailmap.h

@@ -1,7 +1,7 @@
 #ifndef MAILMAP_H
 #define MAILMAP_H
 
-int read_mailmap(struct string_list *map, const char *filename, char **repo_abbrev);
+int read_mailmap(struct string_list *map, char **repo_abbrev);
 int map_email(struct string_list *mailmap, const char *email, char *name, int maxlen);
 
 #endif

pretty.c

@@ -312,7 +312,7 @@ static int mailmap_name(struct strbuf *sb, const char *email)
 
 	if (!mail_map) {
 		mail_map = xcalloc(1, sizeof(*mail_map));
-		read_mailmap(mail_map, ".mailmap", NULL);
+		read_mailmap(mail_map, NULL);
 	}
 
 	if (!mail_map->nr)

t/t4203-mailmap.sh

@@ -0,0 +1,109 @@
+#!/bin/sh
+
+test_description='.mailmap configurations'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	echo one >one &&
+	git add one &&
+	test_tick &&
+	git commit -m initial &&
+	echo two >>one &&
+	git add one &&
+	git commit --author "nick1 <bugs@company.xx>" -m second
+'
+
+cat >expect <<\EOF
+A U Thor (1):
+      initial
+
+nick1 (1):
+      second
+
+EOF
+
+test_expect_success 'No mailmap' '
+	git shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<\EOF
+Repo Guy (1):
+      initial
+
+nick1 (1):
+      second
+
+EOF
+
+test_expect_success 'default .mailmap' '
+	echo "Repo Guy <author@example.com>" > .mailmap &&
+	git shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
+# Using a mailmap file in a subdirectory of the repo here, but
+# could just as well have been a file outside of the repository
+cat >expect <<\EOF
+Internal Guy (1):
+      second
+
+Repo Guy (1):
+      initial
+
+EOF
+test_expect_success 'mailmap.file set' '
+	mkdir internal_mailmap &&
+	echo "Internal Guy <bugs@company.xx>" > internal_mailmap/.mailmap &&
+	git config mailmap.file internal_mailmap/.mailmap &&
+	git shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<\EOF
+External Guy (1):
+      initial
+
+Internal Guy (1):
+      second
+
+EOF
+test_expect_success 'mailmap.file override' '
+	echo "External Guy <author@example.com>" >> internal_mailmap/.mailmap &&
+	git config mailmap.file internal_mailmap/.mailmap &&
+	git shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<\EOF
+Repo Guy (1):
+      initial
+
+nick1 (1):
+      second
+
+EOF
+
+test_expect_success 'mailmap.file non-existant' '
+	rm internal_mailmap/.mailmap &&
+	rmdir internal_mailmap &&
+	git shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<\EOF
+A U Thor (1):
+      initial
+
+nick1 (1):
+      second
+
+EOF
+test_expect_success 'No mailmap files, but configured' '
+	rm .mailmap &&
+	git shortlog HEAD >actual &&
+	test_cmp expect actual
+'
+
+test_done