builtin-blame: Reencode commit messages according to git-log rules.

Currently git-blame outputs text from the commit messages
(e.g. the author name and the summary string) as-is, without
even providing any information about the encoding used for
the data. It makes interpreting the data in multilingual
environment very difficult.

This commit changes the blame implementation to recode the
messages using the rules used by other commands like git-log.
Namely, the target encoding can be specified through the
i18n.commitEncoding or i18n.logOutputEncoding options, or
directly on the command line using the --encoding parameter.

Converting the encoding before output seems to be more
friendly to the porcelain tools than simply providing the
value of the encoding header, and does not require changing
the output format.

If anybody needs the old behavior, it is possible to
achieve it by specifying --encoding=none.

Signed-off-by: Alexander Gavrilov <angavrilov@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

4 files changed, 98 insertions, 0 deletions

diff --git a/t/t8005-blame-i18n.sh b/t/t8005-blame-i18n.sh
new file mode 100755
index 0000000000..4470a92bb2
--- /dev/null
+++ b/t/t8005-blame-i18n.sh
@@ -0,0 +1,92 @@
+#!/bin/sh
+
+test_description='git blame encoding conversion'
+. ./test-lib.sh
+
+. "$TEST_DIRECTORY"/t8005/utf8.txt
+. "$TEST_DIRECTORY"/t8005/cp1251.txt
+. "$TEST_DIRECTORY"/t8005/sjis.txt
+
+test_expect_success 'setup the repository' '
+	# Create the file
+	echo "UTF-8 LINE" > file &&
+	git add file &&
+	git commit --author "$UTF8_NAME <utf8@localhost>" -m "$UTF8_MSG" &&
+
+	echo "CP1251 LINE" >> file &&
+	git add file &&
+	git config i18n.commitencoding cp1251 &&
+	git commit --author "$CP1251_NAME <cp1251@localhost>" -m "$CP1251_MSG" &&
+
+	echo "SJIS LINE" >> file &&
+	git add file &&
+	git config i18n.commitencoding shift-jis &&
+	git commit --author "$SJIS_NAME <sjis@localhost>" -m "$SJIS_MSG"
+'
+
+cat >expected <<EOF
+author $SJIS_NAME
+summary $SJIS_MSG
+author $SJIS_NAME
+summary $SJIS_MSG
+author $SJIS_NAME
+summary $SJIS_MSG
+EOF
+
+test_expect_success \
+	'blame respects i18n.commitencoding' '
+	git blame --incremental file | \
+		grep "^\(author\|summary\) " > actual &&
+	test_cmp actual expected
+'
+
+cat >expected <<EOF
+author $CP1251_NAME
+summary $CP1251_MSG
+author $CP1251_NAME
+summary $CP1251_MSG
+author $CP1251_NAME
+summary $CP1251_MSG
+EOF
+
+test_expect_success \
+	'blame respects i18n.logoutputencoding' '
+	git config i18n.logoutputencoding cp1251 &&
+	git blame --incremental file | \
+		grep "^\(author\|summary\) " > actual &&
+	test_cmp actual expected
+'
+
+cat >expected <<EOF
+author $UTF8_NAME
+summary $UTF8_MSG
+author $UTF8_NAME
+summary $UTF8_MSG
+author $UTF8_NAME
+summary $UTF8_MSG
+EOF
+
+test_expect_success \
+	'blame respects --encoding=utf-8' '
+	git blame --incremental --encoding=utf-8 file | \
+		grep "^\(author\|summary\) " > actual &&
+	test_cmp actual expected
+'
+
+cat >expected <<EOF
+author $SJIS_NAME
+summary $SJIS_MSG
+author $CP1251_NAME
+summary $CP1251_MSG
+author $UTF8_NAME
+summary $UTF8_MSG
+EOF
+
+test_expect_success \
+	'blame respects --encoding=none' '
+	git blame --incremental --encoding=none file | \
+		grep "^\(author\|summary\) " > actual &&
+	test_cmp actual expected
+'
+
+test_done
diff --git a/t/t8005/cp1251.txt b/t/t8005/cp1251.txt
new file mode 100644
index 0000000000..ce41e98b81
--- /dev/null
+++ b/t/t8005/cp1251.txt
@@ -0,0 +1,2 @@
+CP1251_NAME="���� �������� �������"
+CP1251_MSG="�������� ���������"
diff --git a/t/t8005/sjis.txt b/t/t8005/sjis.txt
new file mode 100644
index 0000000000..2ccfbad207
--- /dev/null
+++ b/t/t8005/sjis.txt
@@ -0,0 +1,2 @@
+SJIS_NAME="�I�r�p�~ �P�u�������r�y�� �R�y�t�������r"
+SJIS_MSG="�S�u�������r���u �������q���u�~�y�u"
diff --git a/t/t8005/utf8.txt b/t/t8005/utf8.txt
new file mode 100644
index 0000000000..f46cfc56d8
--- /dev/null
+++ b/t/t8005/utf8.txt
@@ -0,0 +1,2 @@
+UTF8_NAME="Иван Петрович Сидоров"
+UTF8_MSG="Тестовое сообщение"