From f948768a1f26810def56330513a518dfa439795c Mon Sep 17 00:00:00 2001
From: Ole Tange <ole@tange.dk>
Date: Tue, 12 Feb 2013 21:52:01 +0100
Subject: [PATCH] parallel: Negative positional arguments (no context. No -X).

---
 src/parallel                                | 9 +++++----
 testsuite/tests-to-run/parallel-local164.sh | 6 ++++--
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/parallel b/src/parallel
index a4ee96eb..6fb75e60 100755
--- a/src/parallel
+++ b/src/parallel
@@ -631,7 +631,7 @@ sub get_options_from_array {
 sub parse_options {
     # Returns: N/A
     # Defaults:
-    $Global::version = 20130131;
+    $Global::version = 20130212;
     $Global::progname = 'parallel';
     $Global::infinity = 2**31;
     $Global::debug = 0;
@@ -4739,6 +4739,7 @@ sub simple_replace_placeholders {
 	# Merge arguments from records into args for easy access
 	CORE::push @args, @$record;
     }
+    my $n = $#args+1;
     # Which replace strings are used?
     # {#} {} {/} {//} {.} {/.} {n} {n/} {n//} {n.} {n/.}
     for my $used (keys %{$self->{'replacecount'}}) {
@@ -4747,9 +4748,9 @@ sub simple_replace_placeholders {
 	    # {} {/} {//} {.} {/.}
 	    $replace{$Global::replace{$used}} =
 		join(" ", map { $_->replace($used) } @args);
-	} elsif($used =~ /^\{(\d+)(|\/|\/\/|\.|\/\.)\}$/) {
-	    # {n} {n/} {n//} {n.} {n/.}
-	    my $positional = $1; # number if any
+	} elsif($used =~ /^\{(-?\d+)(|\/|\/\/|\.|\/\.)\}$/) {
+	    # {n} {n/} {n//} {n.} {n/.} {-n} {-n/} {-n//} {-n.} {-n/.}
+	    my $positional = $1 > 0 ? $1 : $n+$1+1;
 	    my $replacementfunction = "{".::undef_as_empty($2)."}"; # {} {/} {//} {.} or {/.}
 	    # If -q then the replacementstrings will be quoted, too
 	    # {1.} -> \{1.\}
diff --git a/testsuite/tests-to-run/parallel-local164.sh b/testsuite/tests-to-run/parallel-local164.sh
index 997ad026..9ae789c6 100644
--- a/testsuite/tests-to-run/parallel-local164.sh
+++ b/testsuite/tests-to-run/parallel-local164.sh
@@ -129,8 +129,10 @@ echo '### --resume -k'
   parallel -k --resume --joblog /tmp/joblog-resume echo job{}id\;exit 0 ::: 0 1 2 3 0 5 6 7
 
 echo '### Negative replacement strings'
-  parallel  -N 6 echo {-1}orrec{1} ::: t B C D E c
-  parallel  -N 6 echo {-1}orrect ::: A B C D E c
+  parallel -X -j1 -N 6 echo {-1}orrec{1} ::: t B X D E c
+  parallel -N 6 echo {-1}orrect ::: A B X D E c
+  parallel --colsep ' ' echo '{2} + {4} = {2} + {-1}=' '$(( {2} + {-1} ))' ::: "1 2 3 4"
+  parallel --colsep ' ' echo '{-3}orrect' ::: "1 c 3 4"
 
 
 EOF