patch 8.1.2289: after :diffsplit closing the window does not disable diff
Problem: After :diffsplit closing the window does not disable diff.
Solution: Add "closeoff" to 'diffopt' and add it to the default.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 738dc7f..42c7510 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -2591,7 +2591,7 @@
security reasons.
*'dip'* *'diffopt'*
-'diffopt' 'dip' string (default "internal,filler")
+'diffopt' 'dip' string (default "internal,filler,closeoff")
global
{not available when compiled without the |+diff|
feature}
@@ -2650,6 +2650,12 @@
vertical Start diff mode with vertical splits (unless
explicitly specified otherwise).
+ closeoff When a window is closed where 'diff' is set
+ and there is only one window remaining in the
+ same tab page with 'diff' set, execute
+ `:diffoff` in that window. This undoes a
+ `:diffsplit` command.
+
hiddenoff Do not use diff mode for a buffer when it
becomes hidden.
@@ -2933,6 +2939,9 @@
won't work by default.
NOTE: This option is set to the Vi default value when 'compatible' is
set and to the Vim default value when 'compatible' is reset.
+ NOTE: when this option is off then the |modifyOtherKeys| functionality
+ is disabled while in Insert mode to avoid ending Insert mode with any
+ key that has a modifier.
*'eventignore'* *'ei'*
'eventignore' 'ei' string (default "")