Describe flymake-start-on-save-buffer in manual and NEWS

Fixes: bug#31738

* doc/misc/flymake.texi (Using Flymake, Customizable variables):
Mention flymake-start-on-save-buffer.

* etc/NEWS: Mention flymake-start-on-save-buffer.

2 files changed, 11 insertions, 0 deletions

diff --git a/doc/misc/flymake.texi b/doc/misc/flymake.texi
index e7f4da75bb9..502d408f2b8 100644
--- a/doc/misc/flymake.texi
+++ b/doc/misc/flymake.texi
@@ -84,6 +84,10 @@ Syntax check is done ``on-the-fly''.  It is started whenever
 @code{flymake-start-on-flymake-mode} is nil;
 
 @item
+the buffer is saved, unless @code{flymake-start-on-save-buffer} is
+nil;
+
+@item
 a newline character is added to the buffer, unless
 @code{flymake-start-syntax-check-on-newline} is nil;
 
@@ -220,6 +224,10 @@ after a newline character is inserted into the buffer.
 A boolean flag indicating whether to start syntax check immediately
 after enabling @code{flymake-mode}.
 
+@item flymake-start-on-save-buffer
+A boolean flag indicating whether to start syntax check after saving
+the buffer.
+
 @item flymake-error
 A custom face for highlighting regions for which an error has been
 reported.
diff --git a/etc/NEWS b/etc/NEWS
index 3282340f914..46a57b1888c 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -183,6 +183,9 @@ shown in the currently selected window.
 You should instead set properties on known diagnostic symbols, like
 ':error' and ':warning', as demonstrated in the Flymake manual.
 
+*** New customizable variable 'flymake-start-on-save-buffer'
+Control whether Flymake starts checking the buffer on save.
+
 ** Package
 *** New 'package-quickstart' feature
 When 'package-quickstart' is non-nil, package.el precomputes a big autoloads