libdpkg-perl: Make comp_prog and decomp_prog %COMP properties arrays

This will allow storing arguments alongside the command names
themselves.

scripts/Dpkg/Compression.pm

@@ -50,23 +50,23 @@ interact with the set of supported compression methods.
 my $COMP = {
     "gzip" => {
 	"file_ext" => "gz",
-	"comp_prog" => "gzip",
-	"decomp_prog" => "gunzip",
+	"comp_prog" => [ "gzip" ],
+	"decomp_prog" => [ "gunzip" ],
     },
     "bzip2" => {
 	"file_ext" => "bz2",
-	"comp_prog" => "bzip2",
-	"decomp_prog" => "bunzip2",
+	"comp_prog" => [ "bzip2" ],
+	"decomp_prog" => [ "bunzip2" ],
     },
     "lzma" => {
 	"file_ext" => "lzma",
-	"comp_prog" => "lzma",
-	"decomp_prog" => "unlzma",
+	"comp_prog" => [ "lzma" ],
+	"decomp_prog" => [ "unlzma" ],
     },
     "xz" => {
 	"file_ext" => "xz",
-	"comp_prog" => "xz",
-	"decomp_prog" => "unxz",
+	"comp_prog" => [ "xz" ],
+	"decomp_prog" => [ "unxz" ],
     },
 };
 

scripts/Dpkg/Compression/Process.pm

@@ -101,7 +101,7 @@ and its standard output.
 
 sub get_compress_cmdline {
     my ($self) = @_;
-    my @prog = (compression_get_property($self->{"compression"}, "comp_prog"));
+    my @prog = (@{compression_get_property($self->{"compression"}, "comp_prog")});
     my $level = "-" . $self->{"compression_level"};
     $level = "--" . $self->{"compression_level"}
 	    if $self->{"compression_level"} !~ m/^[1-9]$/;
@@ -111,7 +111,7 @@ sub get_compress_cmdline {
 
 sub get_uncompress_cmdline {
     my ($self) = @_;
-    return (compression_get_property($self->{"compression"}, "decomp_prog"));
+    return (@{compression_get_property($self->{"compression"}, "decomp_prog")});
 }
 
 sub _sanity_check {