ref-filter: support different email formats

Currently, ref-filter only supports printing email with angle brackets.

Let's add support for two more email options.
- trim : for email without angle brackets.
- localpart : for the part before the @ sign out of trimmed email

Mentored-by: Christian Couder <chriscool@tuxfamily.org>
Mentored-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Hariom Verma <hariom18599@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-for-each-ref.txt

@@ -230,7 +230,10 @@ These are intended for working on a mix of annotated and lightweight tags.
 
 Fields that have name-email-date tuple as its value (`author`,
 `committer`, and `tagger`) can be suffixed with `name`, `email`,
-and `date` to extract the named component.
+and `date` to extract the named component.  For email fields (`authoremail`,
+`committeremail` and `taggeremail`), `:trim` can be appended to get the email
+without angle brackets, and `:localpart` to get the part before the `@` symbol
+out of the trimmed email.
 
 The message in a commit or a tag object is `contents`, from which
 `contents:<part>` can be used to extract various parts out of:

ref-filter.c

@@ -140,6 +140,9 @@ static struct used_atom {
 			enum { O_FULL, O_LENGTH, O_SHORT } option;
 			unsigned int length;
 		} objectname;
+		struct email_option {
+			enum { EO_RAW, EO_TRIM, EO_LOCALPART } option;
+		} email_option;
 		struct refname_atom refname;
 		char *head;
 	} u;
@@ -377,6 +380,20 @@ static int objectname_atom_parser(const struct ref_format *format, struct used_a
 	return 0;
 }
 
+static int person_email_atom_parser(const struct ref_format *format, struct used_atom *atom,
+				    const char *arg, struct strbuf *err)
+{
+	if (!arg)
+		atom->u.email_option.option = EO_RAW;
+	else if (!strcmp(arg, "trim"))
+		atom->u.email_option.option = EO_TRIM;
+	else if (!strcmp(arg, "localpart"))
+		atom->u.email_option.option = EO_LOCALPART;
+	else
+		return strbuf_addf_ret(err, -1, _("unrecognized email option: %s"), arg);
+	return 0;
+}
+
 static int refname_atom_parser(const struct ref_format *format, struct used_atom *atom,
 			       const char *arg, struct strbuf *err)
 {
@@ -488,15 +505,15 @@ static struct {
 	{ "tag", SOURCE_OBJ },
 	{ "author", SOURCE_OBJ },
 	{ "authorname", SOURCE_OBJ },
-	{ "authoremail", SOURCE_OBJ },
+	{ "authoremail", SOURCE_OBJ, FIELD_STR, person_email_atom_parser },
 	{ "authordate", SOURCE_OBJ, FIELD_TIME },
 	{ "committer", SOURCE_OBJ },
 	{ "committername", SOURCE_OBJ },
-	{ "committeremail", SOURCE_OBJ },
+	{ "committeremail", SOURCE_OBJ, FIELD_STR, person_email_atom_parser },
 	{ "committerdate", SOURCE_OBJ, FIELD_TIME },
 	{ "tagger", SOURCE_OBJ },
 	{ "taggername", SOURCE_OBJ },
-	{ "taggeremail", SOURCE_OBJ },
+	{ "taggeremail", SOURCE_OBJ, FIELD_STR, person_email_atom_parser },
 	{ "taggerdate", SOURCE_OBJ, FIELD_TIME },
 	{ "creator", SOURCE_OBJ },
 	{ "creatordate", SOURCE_OBJ, FIELD_TIME },
@@ -1037,16 +1054,35 @@ static const char *copy_name(const char *buf)
 	return xstrdup("");
 }
 
-static const char *copy_email(const char *buf)
+static const char *copy_email(const char *buf, struct used_atom *atom)
 {
 	const char *email = strchr(buf, '<');
 	const char *eoemail;
 	if (!email)
 		return xstrdup("");
+	switch (atom->u.email_option.option) {
+	case EO_RAW:
+		eoemail = strchr(email, '>');
+		if (eoemail)
+			eoemail++;
+		break;
+	case EO_TRIM:
+		email++;
+		eoemail = strchr(email, '>');
+		break;
+	case EO_LOCALPART:
+		email++;
+		eoemail = strchr(email, '@');
+		if (!eoemail)
 			eoemail = strchr(email, '>');
+		break;
+	default:
+		BUG("unknown email option");
+	}
+
 	if (!eoemail)
 		return xstrdup("");
-	return xmemdupz(email, eoemail + 1 - email);
+	return xmemdupz(email, eoemail - email);
 }
 
 static char *copy_subject(const char *buf, unsigned long len)
@@ -1116,7 +1152,7 @@ static void grab_person(const char *who, struct atom_value *val, int deref, void
 			continue;
 		if (name[wholen] != 0 &&
 		    strcmp(name + wholen, "name") &&
-		    strcmp(name + wholen, "email") &&
+		    !starts_with(name + wholen, "email") &&
 		    !starts_with(name + wholen, "date"))
 			continue;
 		if (!wholine)
@@ -1127,8 +1163,8 @@ static void grab_person(const char *who, struct atom_value *val, int deref, void
 			v->s = copy_line(wholine);
 		else if (!strcmp(name + wholen, "name"))
 			v->s = copy_name(wholine);
-		else if (!strcmp(name + wholen, "email"))
-			v->s = copy_email(wholine);
+		else if (starts_with(name + wholen, "email"))
+			v->s = copy_email(wholine, &used_atom[i]);
 		else if (starts_with(name + wholen, "date"))
 			grab_date(wholine, v, name);
 	}

t/t6300-for-each-ref.sh

@@ -125,15 +125,21 @@ test_atom head '*objecttype' ''
 test_atom head author 'A U Thor <author@example.com> 1151968724 +0200'
 test_atom head authorname 'A U Thor'
 test_atom head authoremail '<author@example.com>'
+test_atom head authoremail:trim 'author@example.com'
+test_atom head authoremail:localpart 'author'
 test_atom head authordate 'Tue Jul 4 01:18:44 2006 +0200'
 test_atom head committer 'C O Mitter <committer@example.com> 1151968723 +0200'
 test_atom head committername 'C O Mitter'
 test_atom head committeremail '<committer@example.com>'
+test_atom head committeremail:trim 'committer@example.com'
+test_atom head committeremail:localpart 'committer'
 test_atom head committerdate 'Tue Jul 4 01:18:43 2006 +0200'
 test_atom head tag ''
 test_atom head tagger ''
 test_atom head taggername ''
 test_atom head taggeremail ''
+test_atom head taggeremail:trim ''
+test_atom head taggeremail:localpart ''
 test_atom head taggerdate ''
 test_atom head creator 'C O Mitter <committer@example.com> 1151968723 +0200'
 test_atom head creatordate 'Tue Jul 4 01:18:43 2006 +0200'
@@ -170,15 +176,21 @@ test_atom tag '*objecttype' 'commit'
 test_atom tag author ''
 test_atom tag authorname ''
 test_atom tag authoremail ''
+test_atom tag authoremail:trim ''
+test_atom tag authoremail:localpart ''
 test_atom tag authordate ''
 test_atom tag committer ''
 test_atom tag committername ''
 test_atom tag committeremail ''
+test_atom tag committeremail:trim ''
+test_atom tag committeremail:localpart ''
 test_atom tag committerdate ''
 test_atom tag tag 'testtag'
 test_atom tag tagger 'C O Mitter <committer@example.com> 1151968725 +0200'
 test_atom tag taggername 'C O Mitter'
 test_atom tag taggeremail '<committer@example.com>'
+test_atom tag taggeremail:trim 'committer@example.com'
+test_atom tag taggeremail:localpart 'committer'
 test_atom tag taggerdate 'Tue Jul 4 01:18:45 2006 +0200'
 test_atom tag creator 'C O Mitter <committer@example.com> 1151968725 +0200'
 test_atom tag creatordate 'Tue Jul 4 01:18:45 2006 +0200'
@@ -564,10 +576,14 @@ test_atom refs/tags/taggerless tag 'taggerless'
 test_atom refs/tags/taggerless tagger ''
 test_atom refs/tags/taggerless taggername ''
 test_atom refs/tags/taggerless taggeremail ''
+test_atom refs/tags/taggerless taggeremail:trim ''
+test_atom refs/tags/taggerless taggeremail:localpart ''
 test_atom refs/tags/taggerless taggerdate ''
 test_atom refs/tags/taggerless committer ''
 test_atom refs/tags/taggerless committername ''
 test_atom refs/tags/taggerless committeremail ''
+test_atom refs/tags/taggerless committeremail:trim ''
+test_atom refs/tags/taggerless committeremail:localpart ''
 test_atom refs/tags/taggerless committerdate ''
 test_atom refs/tags/taggerless subject 'Broken tag'