Dpkg::Substavars: Make the parse method return the number of substvars parsed

debian/changelog

@@ -22,6 +22,8 @@ dpkg (1.18.11) UNRELEASED; urgency=medium
     - Rework keyring hooks in Dpkg::Vendor. Deprecate the keyrings hook, and
       add package-keyrings, archive-keyrings and archive-keyrings-historic
       hooks. Prompted by Johannes Schauer <josch@debian.org>.
+    - Make the Dpkg::Substavars parse() method return the number of substvars
+      parsed.
   * Packaging:
     - Add liblocale-gettext-perl to libdpkg-perl Recommends.
     - Wrap and document dependency relationships.

scripts/Dpkg/Substvars.pm

@@ -195,10 +195,13 @@ Add new substitutions read from $file.
 Add new substitutions read from the filehandle. $desc is used to identify
 the filehandle in error messages.
 
+Returns the number of substitutions that have been parsed with success.
+
 =cut
 
 sub parse {
     my ($self, $fh, $varlistfile) = @_;
+    my $count = 0;
     local $_;
 
     binmode($fh);
@@ -210,7 +213,10 @@ sub parse {
 		  $varlistfile, $.);
 	}
 	$self->set($1, $2);
+        $count++;
     }
+
+    return $count
 }
 
 =item $s->set_version_substvars($sourceversion, $binaryversion)
@@ -399,6 +405,8 @@ sub output {
 
 Obsolete substvar: Emit an error on Source-Version substvar usage.
 
+New return: $s->parse() now returns the number of parsed substvars.
+
 =head2 Version 1.04 (dpkg 1.18.0)
 
 New method: $s->filter().