patch 9.1.0740: incorrect internal diff with empty file

Problem:  incorrect internal diff with an empty file
Solution: Set pointer to NULL, instead of using an empty line file
          (Yukihiro Nakadaira)

When using internal diff, empty file is read as one empty line file.
So result differs from external diff.

closes: #15719

Signed-off-by: Yukihiro Nakadaira <yukihiro.nakadaira@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

diff --git a/src/diff.c b/src/diff.c
index c50670cdf508e8bda8ce1d20379f56760629459b..70e28143996fefc44bf543709085e36177898504 100644 (file)
--- a/src/diff.c
+++ b/src/diff.c
@@ -760,6 +760,13 @@ diff_write_buffer(buf_T *buf, diffin_T *din)
     long       len = 0;
     char_u     *ptr;
 
+    if (buf->b_ml.ml_flags & ML_EMPTY)
+    {
+       din->din_mmfile.ptr = NULL;
+       din->din_mmfile.size = 0;
+       return OK;
+    }
+
     // xdiff requires one big block of memory with all the text.
     for (lnum = 1; lnum <= buf->b_ml.ml_line_count; ++lnum)
        len += ml_get_buf_len(buf, lnum) + 1;

diff --git a/src/testdir/dumps/Test_diff_21.dump b/src/testdir/dumps/Test_diff_21.dump
new file mode 100644 (file)
index 0000000..8fc8c6c
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_21.dump
@@ -0,0 +1,20 @@
+| +0#0000e05#a8a8a8255@1|0+0#0000000#5fd7ff255| @33||+1&#ffffff0| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34
+|~+0&#ffffff0| @35||+1#0000000&| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@34
+|~+0#4040ff13&| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|X+3#0000000&|d|i|f|i|l|e|1| @10|1|,|1| @11|A|l@1| |X+1&&|d|i|f|i|l|e|2| @10|0|,|0|-|1| @9|A|l@1
+|:+0&&> @73

diff --git a/src/testdir/dumps/Test_diff_22.dump b/src/testdir/dumps/Test_diff_22.dump
new file mode 100644 (file)
index 0000000..5ab9ae2
--- /dev/null
+++ b/src/testdir/dumps/Test_diff_22.dump
@@ -0,0 +1,20 @@
+| +0#0000e05#a8a8a8255@1|-+0#4040ff13#afffff255@34||+1#0000000#ffffff0| +0#0000e05#a8a8a8255@1|0+0#0000000#5fd7ff255| @33
+| +0#0000e05#a8a8a8255@1| +0#0000000#ffffff0@34||+1&&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|~| @35||+1#0000000&|~+0#4040ff13&| @35
+|X+3#0000000&|d|i|f|i|l|e|1| @10|0|,|0|-|1| @9|A|l@1| |X+1&&|d|i|f|i|l|e|2| @10|1|,|1| @11|A|l@1
+|:+0&&> @73

diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index 098d5d0fc67c9085d76a68f2c90d4c9add429775..c391f2dc89ef5eeb55f1a7334bde1d8593aecb03 100644 (file)
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -1015,9 +1015,17 @@ func Test_diff_screen()
   call WriteDiffFiles(buf, ['a ', 'x', 'cd', 'ef', 'xx  xx', 'foo', 'bar'], ['a', 'x', 'c d', ' ef', 'xx xx', 'foo', '', 'bar'])
   call VerifyInternal(buf, 'Test_diff_19', " diffopt+=iwhiteeol")
 
-  " Test 19: test diffopt+=iwhiteall
+  " Test 20: test diffopt+=iwhiteall
   call VerifyInternal(buf, 'Test_diff_20', " diffopt+=iwhiteall")
 
+  " Test 21: Delete all lines
+  call WriteDiffFiles(buf, [0], [])
+  call VerifyBoth(buf, "Test_diff_21", "")
+
+  " Test 22: Add line to empty file
+  call WriteDiffFiles(buf, [], [0])
+  call VerifyBoth(buf, "Test_diff_22", "")
+
   " clean up
   call StopVimInTerminal(buf)
   call delete('Xdifile1')

diff --git a/src/version.c b/src/version.c
index f4b75547115804513f381a2316d2fbf88d24f246..4669e37def03a9c37dbe8424b6b6a98e3c34b56c 100644 (file)
--- 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 */
+/**/
+    740,
 /**/
     739,
 /**/