From 14382c8bc96cc8f3985a01ab58c2f4d7b4d9ec85 Mon Sep 17 00:00:00 2001
From: Christian Brabandt <cb@256bit.org>
Date: Thu, 28 Nov 2024 21:59:33 +0100
Subject: [PATCH] patch 9.1.0893: No test that undofile format does not regress

Problem:  No test that undofile format does not regress
Solution: include a sample undofile to make sure we are always able to
          read it

This is so, that we don't unintentionally change the undofile format and
make sure we can load an undo file that has been created by an older
Vim.

closes: #16127

Signed-off-by: Christian Brabandt <cb@256bit.org>
---
 Filelist                               |   1 +
 src/testdir/samples/test_undo.txt      |   3 +++
 src/testdir/samples/test_undo.txt.undo | Bin 0 -> 1405 bytes
 src/testdir/test_undo.vim              |  29 +++++++++++++++++++++++++
 src/version.c                          |   2 ++
 5 files changed, 35 insertions(+)
 create mode 100644 src/testdir/samples/test_undo.txt
 create mode 100644 src/testdir/samples/test_undo.txt.undo

diff --git a/Filelist b/Filelist
index c5b1b3910c..caac66cdbd 100644
--- a/Filelist
+++ b/Filelist
@@ -224,6 +224,7 @@ SRC_ALL =	\
 		src/testdir/samples/*.vim \
 		src/testdir/samples/test000 \
 		src/testdir/samples/test.zip \
+		src/testdir/samples/test_undo.txt.undo \
 		src/testdir/samples/testa.zip \
 		src/testdir/color_ramp.vim \
 		src/testdir/silent.wav \
diff --git a/src/testdir/samples/test_undo.txt b/src/testdir/samples/test_undo.txt
new file mode 100644
index 0000000000..4cb29ea38f
--- /dev/null
+++ b/src/testdir/samples/test_undo.txt
@@ -0,0 +1,3 @@
+one
+two
+three
diff --git a/src/testdir/samples/test_undo.txt.undo b/src/testdir/samples/test_undo.txt.undo
new file mode 100644
index 0000000000000000000000000000000000000000..393af7f34f32c875724d871f0974b0a9b9ea8114
GIT binary patch
literal 1405
zcmWH`%$*;a=aT=Ffoa#&`5TvYc)h&J<n=e>qP6_G<H-lt9GidPVX9L=-sg*t7#J9s
zffxi}G$RrlBnHC_>F%BEEFf7%hWHCW3Iv!S6qtlaK?VK;0o+I=MWak=g#a)*SisT2
z!0=T9%}`KOFqk%iqX{`aLBgOY1Brp74jfHj)gY-+K>ZK^MiVP?G$98zm<^6RWKmee
pA?GcSyFeKcBsLmxpwOT>07e`ew73ID5pr}OA`V#;7;(>60RSD8H1q%f

literal 0
HcmV?d00001

diff --git a/src/testdir/test_undo.vim b/src/testdir/test_undo.vim
index 2e598d35c2..75ee4a5db3 100644
--- a/src/testdir/test_undo.vim
+++ b/src/testdir/test_undo.vim
@@ -884,4 +884,33 @@ func Test_undo_range_normal()
   bwipe!
 endfunc
 
+func Test_load_existing_undofile()
+  CheckFeature persistent_undo
+  sp samples/test_undo.txt
+  let mess=execute(':verbose rundo samples/test_undo.txt.undo')
+  call assert_match('Finished reading undo file', mess)
+
+  call assert_equal(['one', 'two', 'three'], getline(1, '$'))
+  norm! u
+  call assert_equal(['one', 'two'], getline(1, '$'))
+  norm! u
+  call assert_equal(['one'], getline(1, '$'))
+  norm! u
+  call assert_equal([''], getline(1, '$'))
+  let mess = execute(':norm! u')
+  call assert_equal([''], getline(1, '$'))
+  call assert_match('Already at oldest change', mess)
+  exe ":norm! \<c-r>"
+  call assert_equal(['one'], getline(1, '$'))
+  exe ":norm! \<c-r>"
+  call assert_equal(['one', 'two'], getline(1, '$'))
+  exe ":norm! \<c-r>"
+  call assert_equal(['one', 'two', 'three'], getline(1, '$'))
+  let mess = execute(":norm! \<c-r>")
+  call assert_equal(['one', 'two', 'three'], getline(1, '$'))
+  call assert_match('Already at newest change', mess)
+  bw!
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index d5a7899d71..8c4afd0392 100644
--- a/src/version.c
+++ b/src/version.c
@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    893,
 /**/
     892,
 /**/