From 5c793a12e31cbdddcdae0b39de5e32c667366277 Mon Sep 17 00:00:00 2001
From: Steve Hancock <perltidy@users.sourceforge.net>
Date: Fri, 15 Jan 2021 07:55:59 -0800
Subject: [PATCH] Fixed blinker related to large -ci, short line length and
 -bbsbi=2 -bbsb=1

---
 lib/Perl/Tidy/Formatter.pm |  8 ++++++--
 local-docs/BugLog.pod      | 28 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/lib/Perl/Tidy/Formatter.pm b/lib/Perl/Tidy/Formatter.pm
index a5339bfd..5270f5fa 100644
--- a/lib/Perl/Tidy/Formatter.pm
+++ b/lib/Perl/Tidy/Formatter.pm
@@ -7557,8 +7557,12 @@ sub adjust_container_indentation {
         # This is only for list containers
         next unless $self->is_list_by_seqno($seqno);
 
-        # and only for broken lists
-        next unless $ris_broken_container->{$seqno};
+        # and only for broken lists. 
+        # Require container to span 3 or more line to avoid blinkers,
+        # so line difference must be 2 or more.
+        next
+          if ( $ris_broken_container->{$seqno}
+            && $ris_broken_container->{$seqno} <= 1 );
 
         # NOTE: We are adjusting indentation of the opening container. The
         # closing container will normally follow the indentation of the opening
diff --git a/local-docs/BugLog.pod b/local-docs/BugLog.pod
index adacec39..e60c435a 100644
--- a/local-docs/BugLog.pod
+++ b/local-docs/BugLog.pod
@@ -2,6 +2,34 @@
 
 =over 4
 
+=item B<Fixed blinker related to large -ci, short line length and -bbsbi=2 -bbsb=1>
+
+A blinking state was discovered in testing between the following two states
+
+    my$table=
+         [[1,2,3],[2,4,6],[3,6,9],
+         ];
+
+    my$table=
+        [[1,2,3],[2,4,6],[3,6,9],];
+
+with these parameters
+
+    --continuation-indentation=5
+    --maximum-line-length=31
+    --break-before-square-bracket-and-indent=2
+    --break-before-square-bracket=1
+    --noadd-whitespace
+
+The problem was found to be caused by the -bbsb parameters causing
+the indentation level of the first square bracket to change depending
+upon whether the term was broken on input or not.  Two fixes would correct
+this. One is to turn off the option if the -ci=n value exceeds the -i=n
+value. The other is to require a broken container to span at least three
+lines before turning this option on.  The latter option was made
+to sub 'adjust_container_indentation'.  With this change the snippet remains
+stable at the second state above. Fixed 14 Jan 2021.
+
 =item B<Fixed blinker related to large -ci, short line length and -wn>
 
 In random testing with convergence a 'blinker' (oscillating states) was found
-- 
2.39.5