From 00dcbae8d4ba1ae9aa8fce435c6376fdb44e4814 Mon Sep 17 00:00:00 2001
From: Mischa POSLAWSKY <perl@shiar.org>
Date: Sun, 28 Mar 2021 04:51:55 +0200
Subject: [PATCH] negative limit range counting from end

---
 barcat                                | 21 ++++++++++++++++-----
 t/t1505-bottom_range.in               |  1 +
 t/t1505-bottom_range_-L-4-3.out       |  2 ++
 t/t1506-limit_offset.in               |  1 +
 t/t1506-limit_offset_-L-4+2_#TODO.out |  1 +
 5 files changed, 21 insertions(+), 5 deletions(-)
 create mode 120000 t/t1505-bottom_range.in
 create mode 100644 t/t1505-bottom_range_-L-4-3.out
 create mode 120000 t/t1506-limit_offset.in
 create mode 120000 t/t1506-limit_offset_-L-4+2_#TODO.out

diff --git a/barcat b/barcat
index 5d0f85c..0316b64 100755
--- a/barcat
+++ b/barcat
@@ -209,12 +209,21 @@ sub show_lines {
 state $nr =
 	$opt{hidemin} < 0 ? @lines + $opt{hidemin} + 1 :
 	$opt{hidemin};
-@lines or return;
 @lines > $nr or return;
 
+my $limit = $#lines;
+if (defined $opt{hidemax}) {
+	if ($opt{hidemin} and $opt{hidemin} < 0) {
+		$limit -= $opt{hidemax} - 1;
+	}
+	else {
+		$limit = $opt{hidemax} - 1;
+	}
+}
+
 @order = sort { $b <=> $a } @order unless tied @order;
 my $maxval = $opt{maxval} // (
-	$opt{hidemax} ? max grep { length } @values[0 .. $opt{hidemax} - 1] :
+	$opt{hidemax} ? max grep { length } @values[$nr .. $limit] :
 	$order[0]
 ) // 0;
 my $minval = $opt{minval} // min $order[-1] // (), 0;
@@ -277,8 +286,7 @@ say(
 	color(0),
 ) if $opt{header};
 
-while ($nr <= $#lines) {
-	$nr >= $opt{hidemax} and last if defined $opt{hidemax};
+while ($nr <= $limit) {
 	my $val = $values[$nr];
 	my $rel = length $val && $range && ($val - $minval) / $range;
 	my $color = !length $val || !$opt{palette} ? undef :
@@ -320,8 +328,11 @@ say $opt{palette} ? color(0) : '' if $opt{spark};
 sub show_stat {
 	if ($opt{hidemin} or $opt{hidemax}) {
 		my $linemin = $opt{hidemin};
-		$linemin += @lines if $linemin < 0;
 		my $linemax = ($opt{hidemax} || @lines) - 1;
+		if ($linemin < 0) {
+			$linemin += @lines;
+			$linemax = @lines - $linemax;
+		}
 		printf '%.8g of ', $opt{'sum-format'}->(
 			sum(grep {length} @values[$linemin .. $linemax]) // 0
 		);
diff --git a/t/t1505-bottom_range.in b/t/t1505-bottom_range.in
new file mode 120000
index 0000000..1350c85
--- /dev/null
+++ b/t/t1505-bottom_range.in
@@ -0,0 +1 @@
+t1501-end_limit.in
\ No newline at end of file
diff --git a/t/t1505-bottom_range_-L-4-3.out b/t/t1505-bottom_range_-L-4-3.out
new file mode 100644
index 0000000..5ba6aa3
--- /dev/null
+++ b/t/t1505-bottom_range_-L-4-3.out
@@ -0,0 +1,2 @@
+4274 -----------------------------------
+3350 ---------------------------
diff --git a/t/t1506-limit_offset.in b/t/t1506-limit_offset.in
new file mode 120000
index 0000000..1350c85
--- /dev/null
+++ b/t/t1506-limit_offset.in
@@ -0,0 +1 @@
+t1501-end_limit.in
\ No newline at end of file
diff --git a/t/t1506-limit_offset_-L-4+2_#TODO.out b/t/t1506-limit_offset_-L-4+2_#TODO.out
new file mode 120000
index 0000000..0f0f456
--- /dev/null
+++ b/t/t1506-limit_offset_-L-4+2_#TODO.out
@@ -0,0 +1 @@
+t1505-bottom_range_-L-4-3_#TODO.out
\ No newline at end of file
-- 
2.30.0