Replace `confess $!' with `confess "$!"', to actually print errno

  $ perl -e 'use Carp; open X, ">/dev/eacces" or die $!'
  Permission denied at -e line 1.
  $ perl -e 'use Carp; open X, ">/dev/eacces" or confess $!'
   at -e line 1.
  $ perl -e 'use Carp; open X, ">/dev/eacces" or confess "$!"'
  Permission denied at -e line 1.
  $

confess will get references to its arguments in @_.  Its documentation
says it saves/restores $!.  I conjecture that these interact as we see
here:
  $ perl -e '$!=1; sub x { print ">@_<\n"; }  x $!;'
  >Operation not permitted<
  $ perl -e '$!=1; sub x { local $!; print ">@_<\n"; }  x $!;'
  ><

Quoting "$!" averts the reference (and it will also ensure that we
get the string value of $!, in case confess were to do anything in the
future which would mess that up).

This commit was made like this:

  perl -i -pe 's/confess \$!/confess "\$!"/g' dgit
  perl -i -pe 's/confess \$!/confess "\$!"/g' git-debrebase
  perl -i -pe 's/confess \$!/confess "\$!"/g' Debian/Dgit.pm

I have manually reviewed each hunk and it all looks good to me.

Closes: #929549
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

1 files changed, 21 insertions, 21 deletions

diff --git a/git-debrebase b/git-debrebase
index efb0cea..71bf39d 100755
--- a/git-debrebase
+++ b/git-debrebase
@@ -144,10 +144,10 @@ sub run_ref_updates_now ($$) {
 
     my @upd_cmd = (git_update_ref_cmd "debrebase: $mrest", qw(--stdin));
     debugcmd '>|', @upd_cmd;
-    open U, "|-", @upd_cmd or confess $!;
+    open U, "|-", @upd_cmd or confess "$!";
     foreach (@$updates) {
 	printdebug ">= ", $_, "\n";
-	print U $_, "\n" or confess $!;
+	print U $_, "\n" or confess "$!";
     }
     printdebug ">\$\n";
     close U or failedcmd @upd_cmd;
@@ -611,7 +611,7 @@ sub merge_series ($$$;@) {
 	    if ($any) {
 		open S, $seriesfile or confess "$seriesfile $!";
 		while (my $patch = <S>) {
-		    chomp $patch or confess $!;
+		    chomp $patch or confess "$!";
 		    $prereq{$patch} //= {};
 		    foreach my $earlier (@earlier) {
 			$prereq{$patch}{$earlier}{$s}++ and confess;
@@ -708,7 +708,7 @@ sub merge_series ($$$;@) {
 	    };
 	};
 
-	open NS, '>', $seriesfile or confess $!;
+	open NS, '>', $seriesfile or confess "$!";
 
 	while (keys %prereq) {
 	    my $best;
@@ -723,7 +723,7 @@ sub merge_series ($$$;@) {
 		$best = $try;
 	    }
 	    printdebug "merge_series series next $best\n";
-	    print NS "$best\n" or confess $!;
+	    print NS "$best\n" or confess "$!";
 	    delete $prereq{$best};
 	    foreach my $gp (values %prereq) {
 		delete $gp->{$best};
@@ -765,9 +765,9 @@ sub merge_series_patchqueue_convert ($$$) {
 	    my $tree = cmdoutput @git, qw(write-tree);
 	    $commit =~ s{^parent (\S+)$}{parent $build}m or confess;
 	    $commit =~ s{^tree (\S+)$}{tree $tree}m      or confess;
-	    open C, ">", "../mcommit" or confess $!;
-	    print C $commit or confess $!;
-	    close C or confess $!;
+	    open C, ">", "../mcommit" or confess "$!";
+	    print C $commit or confess "$!";
+	    close C or confess "$!";
 	    $build = cmdoutput @git, qw(hash-object -w -t commit ../mcommit);
 	}
 	$result = $build;
@@ -1586,7 +1586,7 @@ sub walk ($;$$$) {
     confess __ "internal error" unless $build eq (pop @processed)->{CommitId};
 
     in_workarea sub {
-	mkdir $rd or $!==EEXIST or confess $!;
+	mkdir $rd or $!==EEXIST or confess "$!";
 	my $current_method;
 	my $want_debian = $build;
 	my $want_upstream = $build;
@@ -1696,9 +1696,9 @@ sub walk ($;$$$) {
 			or confess "$ch ?";
 		}
 		my $cf = "$rd/m$rewriting";
-		open CD, ">", $cf or confess $!;
-		print CD $ch, "\n", $cl->{Msg} or confess $!;
-		close CD or confess $!;
+		open CD, ">", $cf or confess "$!";
+		print CD $ch, "\n", $cl->{Msg} or confess "$!";
+		close CD or confess "$!";
 		my @cmd = (@git, qw(hash-object));
 		push @cmd, qw(-w) if $rewriting;
 		push @cmd, qw(-t commit), $cf;
@@ -1811,7 +1811,7 @@ sub cmd_analyse () {
 	$old = git_rev_parse 'HEAD';
     }
     my ($dummy,$breakwater) = walk $old, 1,*STDOUT;
-    STDOUT->error and confess $!;
+    STDOUT->error and confess "$!";
 }
 
 sub ffq_check ($;$$) {
@@ -1828,7 +1828,7 @@ sub ffq_check ($;$$) {
     # normally $currentval should be HEAD
     my ($currentval, $ff, $notff) =@_;
 
-    $ff //= sub { print $_[0] or confess $!; };
+    $ff //= sub { print $_[0] or confess "$!"; };
     $notff //= \&snag;
 
     my ($status, $message, $current, $ffq_prev, $gdrlast)
@@ -2261,7 +2261,7 @@ sub cmd_record_ffq_prev () {
     badusage "no arguments allowed" if @ARGV;
     my ($status, $msg) = record_ffq_prev_deferred();
     if ($status eq 'exists' && $opt_noop_ok) {
-	print __ "Previous head already recorded\n" or confess $!;
+	print __ "Previous head already recorded\n" or confess "$!";
     } elsif ($status eq 'deferred') {
 	run_deferred_updates 'record-ffq-prev';
     } else {
@@ -2272,13 +2272,13 @@ sub cmd_record_ffq_prev () {
 sub cmd_anchor () {
     badusage __ "no arguments allowed" if @ARGV;
     my ($anchor, $bw) = keycommits +(git_rev_parse 'HEAD'), 0,0;
-    print "$anchor\n" or confess $!;
+    print "$anchor\n" or confess "$!";
 }
 
 sub cmd_breakwater () {
     badusage __ "no arguments allowed" if @ARGV;
     my ($anchor, $bw) = keycommits +(git_rev_parse 'HEAD'), 0,0;
-    print "$bw\n" or confess $!;
+    print "$bw\n" or confess "$!";
 }
 
 sub cmd_status () {
@@ -2311,7 +2311,7 @@ sub cmd_status () {
 
     my $prcommitinfo = sub {
 	my ($cid) = @_;
-	flush STDOUT or confess $!;
+	flush STDOUT or confess "$!";
 	runcmd @git, qw(--no-pager log -n1),
 	    '--pretty=format:    %h %s%n',
 	    $cid;
@@ -2674,7 +2674,7 @@ END
     };
 
     complete_convert_from $old_head, $work, $gdrlastinfo, 'convert-from-gbp';
-    print f_ <<END, $us or confess $!;
+    print f_ <<END, $us or confess "$!";
 %s: converted from patched-unapplied (gbp) branch format, OK
 END
 }
@@ -2703,7 +2703,7 @@ sub cmd_convert_to_gbp () {
     }
     snags_maybe_bail();
     update_head_checkout $head, $out, "convert to gbp (v0)";
-    print f_ <<END, $us,$us,$us or confess $!;
+    print f_ <<END, $us,$us,$us or confess "$!";
 %s: converted to git-buildpackage branch format
 %s: WARNING: do not now run "git-debrebase" any more
 %s: WARNING: doing so would drop all upstream patches!
@@ -3030,7 +3030,7 @@ getoptions_main
 	       push @$opt_defaultcmd_interactive, @ARGV;
 	       @ARGV=();
 	   },
-	   'help' => sub { print __ $usage_message or confess $!; finish 0; },
+	   'help' => sub { print __ $usage_message or confess "$!"; finish 0; },
 	   );
 
 initdebug('git-debrebase ');