Bug#644021: [checks/{rules,debhelper}] parse continuation lines correctly

[Jakub Wilk <jwilk@debian.org>]

Package: lintian
Version: 2.5.3
Severity: wishlist
Tags: patch

With the attached patch debian/rules parsers in checks/rules and 
checks/debhelper will parse continuation lines correctly.

--
Jakub Wilk

diff --git a/checks/debhelper b/checks/debhelper
--- a/checks/debhelper
+++ b/checks/debhelper
@@ -82,6 +82,9 @@
 open(RULES, '<', "$droot/rules") or fail("cannot read debian/rules: $!");
 
 while (<RULES>) {
+    while (s,\\$,, and defined (my $cont = <RULES>)) {
+        $_ .= $cont;
+    }
     if (/^ifn?(?:eq|def)\s/) {
         $maybe_skipping++;
     } elsif (/^endif\s/) {
@@ -119,7 +122,7 @@
             if ($dhcommand eq 'dh_scrollkeeper') {
                 tag 'dh_scrollkeeper-is-deprecated', "line $.";
             }
-            if ($dhcommand eq 'dh_clean' and m/\s+\-k(?:\s+.*)?$/) {
+            if ($dhcommand eq 'dh_clean' and m/\s+\-k(?:\s+.*)?$/s) {
                 $seendhcleank = 1;
             }
         }
diff --git a/checks/rules b/checks/rules
--- a/checks/rules
+++ b/checks/rules
@@ -76,13 +76,13 @@
     (
      [ 'ant | ant1.7' => qr'^\t\s*(\S+=\S+\s+)*ant\s' ],
      [ debhelper => qr'^\t\s*dh_.+' ],
-     [ 'dh-ocaml, ocaml-nox | ocaml' => qr'^\t\s*(?:dh_ocamlinit|dh\s.*--with(?:=|\s+)(?:\S+,)*ocaml)\s' ],
+     [ 'dh-ocaml, ocaml-nox | ocaml' => qr'^\t\s*(?:dh_ocamlinit|dh\s.*--with(?:=|\s+)(?:\S+,)*ocaml)\s's ],
      [ dpatch => qr'^\t\s*(\S+=\S+\s+)*dpatch\s' ],
      [ 'po-debconf' => qr'^\t\s*debconf-updatepo\s' ],
      [ $PYTHON_DEPEND => qr'^\t\s*python\s', 'missing-python-build-dependency' ],
      [ $PYTHON3_DEPEND => qr'^\t\s*python3\s', 'missing-python-build-dependency' ],
      [ $ANYPYTHON_DEPEND => qr'\ssetup\.py\b', 'missing-python-build-dependency' ],
-     [ quilt => qr'^\t\s*dh\s.*--with(?:=|\s+)(?:\S+,)*quilt' ],
+     [ quilt => qr'^\t\s*dh\s.*--with(?:=|\s+)(?:\S+,)*quilt's ],
      [ quilt => qr'^\t\s*(\S+=\S+\s+)*quilt\s' ],
      [ yada => qr'^\t\s*yada\s' ],
     );
@@ -156,6 +156,9 @@
 my $uses_makefile_pl = 0;
 my %variables;
 while (<RULES>) {
+    while (s,\\$,, and defined (my $cont = <RULES>)) {
+        $_ .= $cont;
+    }
     next if /^\s*\#/;
     if (m/^\s*[s-]?include\s+(\S++)/o){
         my $makefile = $1;
@@ -185,8 +188,8 @@
     if (/\$[\(\{]PWD[\)\}]/) {
         tag 'debian-rules-uses-pwd', "line $.";
     }
-    if (m/^\t\s*-(?:\$[\(\{]MAKE[\}\)]|make)\s.*(?:dist)?clean/ ||
-        m/^\t\s*(?:\$[\(\{]MAKE[\}\)]|make)\s(?:.*\s)?-\w*i.*(?:dist)?clean/) {
+    if (m/^\t\s*-(?:\$[\(\{]MAKE[\}\)]|make)\s.*(?:dist)?clean/s ||
+        m/^\t\s*(?:\$[\(\{]MAKE[\}\)]|make)\s(?:.*\s)?-\w*i.*(?:dist)?clean/s) {
         tag 'debian-rules-ignores-make-clean-error', "line $.";
     }
     if (/\$[\(\{]DEB_BUILD_OPTS[\)\}]/) {
@@ -198,12 +201,12 @@
     if (m/\bDEB_[^_ \t]+FLAGS_(?:SET|APPEND)\b/o) {
         tag 'debian-rules-uses-or-modifies-user-only-variable', "line $.";
     }
-    if ($uses_makefile_pl && m/install.*PREFIX/ && !/DESTDIR/) {
+    if ($uses_makefile_pl && m/install.*PREFIX/s && !/DESTDIR/) {
         tag 'debian-rules-makemaker-prefix-is-deprecated', "line $.";
     }
 
     # General assignment - save the variable
-    if (/^\s*(?:\S+\s+)*?(\S+)\s*([:\?\+])?=\s*(.*+)?$/o) {
+    if (/^\s*(?:\S+\s+)*?(\S+)\s*([:\?\+])?=\s*(.*+)?$/so) {
         # This is far too simple from a theoretical PoV, but should do
         # rather well.
         my ($var, $atype, $value) = ($1, $2, $3);
@@ -234,7 +237,7 @@
     # Listing a rule as a dependency of .PHONY is sufficient to make it
     # present for the purposes of GNU make and therefore the Policy
     # requirement.
-    if (/^(?:[^:]+\s)?\.PHONY(?:\s[^:]+)?:(.+)/) {
+    if (/^(?:[^:]+\s)?\.PHONY(?:\s[^:]+)?:(.+)/s) {
         my @targets = split (' ', $1);
         local $_;
         for (@targets) {
@@ -261,7 +264,7 @@
         next; #.PHONY implies the rest will not match
     }
 
-    if (!/^ifn?(?:eq|def)\s/ && m/^([^\s:][^:]*):+(.*)/) {
+    if (!/^ifn?(?:eq|def)\s/ && m/^([^\s:][^:]*):+(.*)/s) {
         @current_targets = split (' ', $1);
         my @depends = map {
             $_ = quotemeta $_;