patch 9.1.0140: cursor on wrong row after 1 char 'below' virtual text when EOL is shown

Problem:  The cursor screen row was incorrectly being calculated when the
          cursor follows a 1 character text_align 'below' virtual text line,
          resulting in the cursor being shown on the wrong line.
          This was caused by a cell size of 2 instead of 1 being used for the EOL
          character, which propagated to the calculation of space for putting the
          'below' virtual text on its own line. (rickhowe)
Solution: Fix the size used for the EOL character in calculating the
          cursor's screen position (Dylan Thacker-Smith)

fixes: #11959
related: #12028
closes: #14096

Signed-off-by: Dylan Thacker-Smith <dylan.ah.smith@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/charset.c b/src/charset.c
index 919885d..9f4c0ae 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -1160,8 +1160,12 @@
      * First get the normal size, without 'linebreak' or text properties
      */
     size = win_chartabsize(wp, s, vcol);
-    if (*s == NUL && !has_lcs_eol)
-	size = 0;  // NUL is not displayed
+    if (*s == NUL)
+    {
+	// 1 cell for EOL list char (if present), as opposed to the two cell ^@
+	// for a NUL character in the text.
+	size = has_lcs_eol ? 1 : 0;
+    }
 # ifdef FEAT_LINEBREAK
     int is_doublewidth = has_mbyte && size == 2 && MB_BYTE2LEN(*s) > 1;
 # endif
diff --git a/src/testdir/dumps/Test_prop_above_below_empty_1.dump b/src/testdir/dumps/Test_prop_above_below_empty_1.dump
index f470016..1cc6d01 100644
--- a/src/testdir/dumps/Test_prop_above_below_empty_1.dump
+++ b/src/testdir/dumps/Test_prop_above_below_empty_1.dump
@@ -1,16 +1,16 @@
-| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|1| |1+0#0000000&@7| @47
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|2| | +0#0000000&@55
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|3| |3+0#0000000&@8| @46
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|4| | +0#0000000&@55
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|5| >5+0#0000000&@10| @44
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
 @42|5|,|1|-|5|7| @7|A|l@1| 
diff --git a/src/testdir/dumps/Test_prop_above_below_empty_2.dump b/src/testdir/dumps/Test_prop_above_below_empty_2.dump
index 3954a4b..db11724 100644
--- a/src/testdir/dumps/Test_prop_above_below_empty_2.dump
+++ b/src/testdir/dumps/Test_prop_above_below_empty_2.dump
@@ -1,16 +1,16 @@
-| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|1| |1+0#0000000&@7|$+0#4040ff13&| +0#0000000&@46
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|2| |$+0#4040ff13&| +0#0000000&@54
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|3| |3+0#0000000&@8|$+0#4040ff13&| +0#0000000&@45
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|4| |$+0#4040ff13&| +0#0000000&@54
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|5| >5+0#0000000&@10|$+0#4040ff13&| +0#0000000&@43
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
 |:|s|e|t| |l|i|s|t| @32|5|,|1|-|5|7| @7|A|l@1| 
diff --git a/src/testdir/dumps/Test_prop_above_below_empty_3.dump b/src/testdir/dumps/Test_prop_above_below_empty_3.dump
index 27f9eec..78f30b7 100644
--- a/src/testdir/dumps/Test_prop_above_below_empty_3.dump
+++ b/src/testdir/dumps/Test_prop_above_below_empty_3.dump
@@ -1,16 +1,16 @@
-| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|1| |1+0#0000000&@7| | +0&#ffd7d7255| +0&#ffffff0@45
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|2| | +0#0000000&@8| +0&#ffd7d7255| +0&#ffffff0@45
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|3| |3+0#0000000&@8| +0&#ffd7d7255| +0&#ffffff0@45
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|4| | +0#0000000&@8| +0&#ffd7d7255| +0&#ffffff0@45
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|5| >5+0#0000000&@8|5+0&#ffd7d7255|5+0&#ffffff0| @44
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
 |:| @40|5|,|1|-|5|7| @7|A|l@1| 
diff --git a/src/testdir/dumps/Test_prop_above_below_empty_4.dump b/src/testdir/dumps/Test_prop_above_below_empty_4.dump
index cc3c27d..2c7bf4d 100644
--- a/src/testdir/dumps/Test_prop_above_below_empty_4.dump
+++ b/src/testdir/dumps/Test_prop_above_below_empty_4.dump
@@ -1,16 +1,16 @@
-| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|4| |1+0#0000000&@7| @47
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|3| | +0#0000000&@55
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|2| |3+0#0000000&@8| @46
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|1| | +0#0000000&@55
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 |5+0#af5f00255&| @2>5+0#0000000&@10| @44
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
 |:| @40|5|,|1|-|5|7| @7|A|l@1| 
diff --git a/src/testdir/dumps/Test_prop_above_below_empty_5.dump b/src/testdir/dumps/Test_prop_above_below_empty_5.dump
index 5ee4d80..1928ea2 100644
--- a/src/testdir/dumps/Test_prop_above_below_empty_5.dump
+++ b/src/testdir/dumps/Test_prop_above_below_empty_5.dump
@@ -1,16 +1,16 @@
-| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255#ffffff0@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|2| |1+0#0000000&@7| @47
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|1| | +0#0000000&@55
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 |3+0#af5f00255&| @2>3+0#0000000&@8| @46
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|1| | +0#0000000&@55
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
-| +0#af5f00255&@3|-+0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
+| +0#af5f00255&@3|-+0#0000001#ffff4012| +0#0000000#ffffff0@54
 | +0#af5f00255&@1|2| |5+0#0000000&@10| @44
-| +0#af5f00255&@3|++0#0000001#ffff4012@2| +0#0000000#ffffff0@52
+| +0#af5f00255&@3|++0#0000001#ffff4012| +0#0000000#ffffff0@54
 |:| @40|3|,|1|-|5|7| @7|A|l@1| 
diff --git a/src/testdir/test_textprop.vim b/src/testdir/test_textprop.vim
index 18ff3df..7542c08 100644
--- a/src/testdir/test_textprop.vim
+++ b/src/testdir/test_textprop.vim
@@ -3075,8 +3075,9 @@
       let vt = 'test'
       call prop_type_add(vt, {'highlight': 'ToDo'})
       for ln in range(1, line('$'))
-        call prop_add(ln, 0, {'type': vt, 'text': '---', 'text_align': 'above'})
-        call prop_add(ln, 0, {'type': vt, 'text': '+++', 'text_align': 'below'})
+        " use 1 character text to test for off-by-one regressions
+        call prop_add(ln, 0, {'type': vt, 'text': '-', 'text_align': 'above'})
+        call prop_add(ln, 0, {'type': vt, 'text': '+', 'text_align': 'below'})
       endfor
       normal G
   END
diff --git a/src/version.c b/src/version.c
index 07d2558..673c707 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    140,
+/**/
     139,
 /**/
     138,