From 5e85e135818984b1952cb77d7ad8766a6acbb9b1 Mon Sep 17 00:00:00 2001
From: Steve Hancock <perltidy@users.sourceforge.net>
Date: Sat, 25 Sep 2021 14:20:33 -0700
Subject: [PATCH] fix issue b1210, very rare instability with -vmll

---
 dev-bin/run_convergence_tests.pl.data | 23 +++++++++++++++++++++++
 lib/Perl/Tidy/Formatter.pm            | 19 +++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/dev-bin/run_convergence_tests.pl.data b/dev-bin/run_convergence_tests.pl.data
index 16f538f3..235e5570 100644
--- a/dev-bin/run_convergence_tests.pl.data
+++ b/dev-bin/run_convergence_tests.pl.data
@@ -7433,6 +7433,29 @@ $bc[
 --vertical-tightness=1
 --weld-nested-containers
 
+==> b1210.in <==
+# S1
+@mo = ( Jan, Feb, Mar, Apr,
+        May, Jun, Jul, Aug,
+        Sep, Oct, Nov, Dec
+);
+
+# S2
+@mo =
+         ( Jan, Feb, Mar, Apr,
+        May, Jun,
+        Jul, Aug, Sep, Oct, Nov, Dec
+         );
+
+
+==> b1210.par <==
+--break-before-paren=1
+--continuation-indentation=9
+--indent-columns=7
+--line-up-parentheses
+--maximum-line-length=34
+--variable-maximum-line-length
+
 ==> b131.in <==
         unless
           ( open( SCORE, "+>>$Score_File" ) )
diff --git a/lib/Perl/Tidy/Formatter.pm b/lib/Perl/Tidy/Formatter.pm
index 177df1f1..fbab11a9 100644
--- a/lib/Perl/Tidy/Formatter.pm
+++ b/lib/Perl/Tidy/Formatter.pm
@@ -18213,6 +18213,25 @@ EOM
         # Number of free columns across the page width for laying out tables
         my $columns = table_columns_available($i_first_comma);
 
+        # Patch for b1210 when -vmll is set.  If we are unable to break after
+        # an opening paren, then the maximum line length for the first line
+        # will be less than the later lines.  So we use the minimum possible.
+        if (   $rOpts_variable_maximum_line_length
+            && $tokens_to_go[$i_opening_paren] eq '('
+            && @i_term_begin
+            && !$old_breakpoint_to_go[$i_opening_paren] )
+        {
+            my $ib   = $i_term_begin[0];
+            my $type = $types_to_go[$ib];
+
+            # So far, the only known instance of this problem is when
+            # a bareword follows an opening paren with -vmll
+            if ( $type eq 'w' ) {
+                my $columns2 = table_columns_available($i_opening_paren);
+                $columns = min( $columns, $columns2 );
+            }
+        }
+
         # Estimated maximum number of fields which fit this space
         # This will be our first guess
         my $number_of_fields_max =
-- 
2.39.5