From patchwork Sat Jul  5 18:00:09 2014
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Subject: [10, of, 11,
 V2] filemerge: use 'util.ellipsis' to trim custom conflict markers
 correctly
From: Katsunori FUJIWARA <foozy@lares.dti.ne.jp>
X-Patchwork-Id: 5114
Message-Id: <21eb3ac84075d72de5ad.1404583209@feefifofum>
To: mercurial-devel@selenic.com
Date: Sun, 06 Jul 2014 03:00:09 +0900

# HG changeset patch
# User FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
# Date 1404583001 -32400
#      Sun Jul 06 02:56:41 2014 +0900
# Node ID 21eb3ac84075d72de5adc097f8fe4bfe1f66c1b8
# Parent  23280cda5ee6b9ee8840d8f487e36d29efb7c95c
filemerge: use 'util.ellipsis' to trim custom conflict markers correctly

Before this patch, filemerge slices byte sequence directly to trim
conflict markers, but this may cause:

  - splitting at intermediate multi-byte sequence

  - incorrect calculation of column width (length of byte sequence is
    different from columns in display in many cases)

This patch uses 'util.ellipsis' to trim custom conflict markers
correctly, even if multi-byte characters are used in them.

diff --git a/mercurial/filemerge.py b/mercurial/filemerge.py
--- a/mercurial/filemerge.py
+++ b/mercurial/filemerge.py
@@ -290,12 +290,8 @@
     if mark:
         mark = mark.splitlines()[0] # split for safety
 
-    # The <<< marks add 8 to the length, and '...' adds three, so max
-    # length of the actual marker is 69.
-    maxlength = 80 - 8 - 3
-    if len(mark) > maxlength:
-        mark = mark[:maxlength] + '...'
-    return mark
+    # 8 for the prefix of conflict marker lines (e.g. '<<<<<<< ')
+    return util.ellipsis(mark, 80 - 8)
 
 _defaultconflictmarker = ('{node|short} ' +
     '{ifeq(tags, "tip", "", "{tags} ")}' +
diff --git a/tests/test-conflict.t b/tests/test-conflict.t
--- a/tests/test-conflict.t
+++ b/tests/test-conflict.t
@@ -72,9 +72,42 @@
   something
   >>>>>>> other: test 1
 
+Verify line trimming of custom conflict marker using multi-byte characters
+
+  $ hg up -q --clean .
+  $ python <<EOF
+  > fp = open('logfile', 'w')
+  > fp.write('12345678901234567890123456789012345678901234567890' +
+  >          '1234567890') # there are 5 more columns for 80 columns
+  > 
+  > # 2 x 4 = 8 columns, but 3 x 4 = 12 bytes
+  > fp.write(u'\u3042\u3044\u3046\u3048'.encode('utf-8'))
+  > 
+  > fp.close()
+  > EOF
+  $ hg add logfile
+  $ hg --encoding utf-8 commit --logfile logfile
+
+  $ cat >> .hg/hgrc <<EOF
+  > [ui]
+  > mergemarkertemplate={desc|firstline}
+  > EOF
+
+  $ hg -q --encoding utf-8 merge 1
+  warning: conflicts during merge.
+  merging a incomplete! (edit conflicts, then use 'hg resolve --mark')
+  [1]
+
+  $ cat a
+  <<<<<<< local: 123456789012345678901234567890123456789012345678901234567890\xe3\x81\x82... (esc)
+  something else
+  =======
+  something
+  >>>>>>> other: branch1
+
 Verify basic conflict markers
 
-  $ hg up -q --clean .
+  $ hg up -q --clean 2
   $ printf "\n[ui]\nmergemarkers=basic\n" >> .hg/hgrc
 
   $ hg merge 1