From 484aa21a6f9ec6090a78b111eb429f9d922e25b9 Mon Sep 17 00:00:00 2001
From: Thomas Koutcher <thomas.koutcher@online.fr>
Date: Sun, 12 Apr 2020 10:49:15 +0200
Subject: [PATCH] Fix wrapping of lines with multibyte characters

Fixes #988
---
 NEWS.adoc                 |  7 ++++
 include/tig/string.h      |  1 -
 src/pager.c               |  4 ++-
 src/string.c              | 21 ++----------
 test/blob/wrap-lines-test | 67 +++++++++++++++++++++------------------
 5 files changed, 49 insertions(+), 51 deletions(-)

diff --git a/NEWS.adoc b/NEWS.adoc
index b75e16a13..7dbea85eb 100644
--- a/NEWS.adoc
+++ b/NEWS.adoc
@@ -1,6 +1,13 @@
 Release notes
 =============
 
+master
+------
+
+Bug fixes:
+
+ - Fix wrapping of lines with multibyte characters. (#988)
+
 tig-2.5.1
 ---------
 
diff --git a/include/tig/string.h b/include/tig/string.h
index 7a2449988..290d313db 100644
--- a/include/tig/string.h
+++ b/include/tig/string.h
@@ -84,7 +84,6 @@ void string_copy_rev_from_commit_line(char *dst, const char *src);
 #define string_concat_path(dst, path1, path2) \
 	string_format(dst, !*path1 || path1[strlen(path1) - 1] == '/' ? "%s%s" : "%s/%s", path1, path2)
 
-size_t string_expanded_length(const char *src, size_t srclen, size_t tabsize, size_t max_size);
 size_t string_expand(char *dst, size_t dstlen, const char *src, int srclen, int tabsize);
 
 char *string_trim_end(char *name);
diff --git a/src/pager.c b/src/pager.c
index 94ea70fb0..9386292e6 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -73,8 +73,10 @@ pager_wrap_line(struct view *view, const char *data, enum line_type type)
 	size_t lineno = 0;
 
 	while (datalen > 0 || !has_first_line) {
+		int width;
+		int trimmed;
 		bool wrapped = !!first_line;
-		size_t linelen = string_expanded_length(data, datalen, opt_tab_size, view->width - !!wrapped);
+		size_t linelen = utf8_length(&data, datalen, 0, &width, view->width, &trimmed, wrapped, opt_tab_size);
 		struct line *line;
 
 		line = add_line_text_at_(view, view->lines, data, linelen, type, 1, wrapped);
diff --git a/src/string.c b/src/string.c
index 57f49cd00..7296508f7 100644
--- a/src/string.c
+++ b/src/string.c
@@ -85,24 +85,6 @@ string_copy_rev_from_commit_line(char *dst, const char *src)
 	string_copy_rev(dst, src + STRING_SIZE("commit "));
 }
 
-size_t
-string_expanded_length(const char *src, size_t srclen, size_t tabsize, size_t max_size)
-{
-	size_t size, pos;
-
-	for (size = pos = 0; pos < srclen && size < max_size; pos++) {
-		if (src[pos] == '\t') {
-			size_t expanded = tabsize - (size % tabsize);
-
-			size += expanded;
-		} else {
-			size++;
-		}
-	}
-
-	return pos;
-}
-
 size_t
 string_expand(char *dst, size_t dstlen, const char *src, int srclen, int tabsize)
 {
@@ -330,7 +312,8 @@ utf8_length(const char **start, int max_chars, size_t skip, int *width, size_t m
 		if (!unicode)
 			break;
 
-		ucwidth = unicode_width(unicode, tab_size);
+		ucwidth = unicode == '\t' ? tab_size - (*width % tab_size) :
+					    utf8proc_charwidth((utf8proc_int32_t) unicode);
 		if (skip > 0) {
 			skip -= ucwidth <= skip ? ucwidth : skip;
 			*start += bytes;
diff --git a/test/blob/wrap-lines-test b/test/blob/wrap-lines-test
index d6414ee83..9ee7a795d 100755
--- a/test/blob/wrap-lines-test
+++ b/test/blob/wrap-lines-test
@@ -17,38 +17,45 @@ set line-graphics = utf-8
 set wrap-lines = true
 EOF
 
-in_work_dir create_repo_from_tgz "$base_dir/files/scala-js-benchmarks.tgz"
+git_init
+
+test_setup_work_dir()
+{
+	printf 'Как пуст, и вял, и ничтожен почти всякий прожитой день! Как мало следов оставляет он за собою! Как бессмысленно глупо пробежали эти часы за часами!\tИван Сергеевич Тургенев\n' >README.md
+	git add README.md
+	git_commit -m "tomorrow"
+}
 
 test_tig
 
 assert_equals 'wrapped.screen' <<EOF
-# Scala.js Benchmarks
-
-This is a port of the Dart
-[benchmark harness](https://github.com/d
-+art-lang/benchmark_harness) to
-[Scala.js](https://github.com/scala-js/s
-+cala-js).
-
-You can see the benchmarks in action
-[here](http://jonas.github.io/scala-js-b
-+enchmarks/).
-
-All derivative work is the copyright of
-+their respective authors and
-distributed under their original license
-+. All original work unless otherwise
-stated is distributed under the [same li
-+cense as
-Scala.js](https://github.com/jonas/scala
-+-js-benchmarks/LICENSE).
-
-## Get started
-
-To run the benchmarks, first install the
-+ Scala.js compiler by following the
-instructions in the [Scala.js README](ht
-+tps://github.com/lampepfl/scala-js).
-
-[blob] README.md - line 1 of 62      28%
+Как пуст, и вял, и ничтожен почти всякий
+ прожитой день! Как мало следов оставляе
+т он за собою! Как бессмысленно глупо пр
+обежали эти часы за часами!       Иван С
+геевич Тургенев
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+[blob] README.md - line 1 of 5      100%
 EOF