Bug#695967: [new check] GFDL invariant

[bastien ROUCARIES <roucaries.bastien@gmail.com>]

Package: lintian
Version: 2.5.10.2
Severity: wishlist
tag: patch

Please found some patch in order to check GFDL liense

diff --git a/checks/cruft b/checks/cruft
index 1121e16..e3a4498 100644
--- a/checks/cruft
+++ b/checks/cruft
@@ -412,11 +412,31 @@ sub find_cruft {
     # test license problem is source file (only text file)
     if (-T $basename) {
         open my $F, '<', $basename or fail "can't open $name: $!";
+        
+        # GFDL state variable
+        my $foundGFDL = 0;
         while (my $line = <$F>) {
           # json evil license
           if ($line =~ m/Software\s+shall\s+be\s+used\s+for\s+Good\s*,?\s*not\s+Evil/i) {
              tag 'license-problem-json-evil', $name;
           }
+          # GFDL state machine
+          if($line =~ m/GNU\s+Free\s+Documentation\s+License/) {
+              $foundGFDL = 1;
+          }
+          if($foundGFDL) {
+              # match in two part in order to not match italic html license example
+              if($line =~ m/with\s+the\s+Invariant\s+Sections\s+being/i) {
+                  if($line !~ m/list\s+their\s+titles/i) {
+                      tag 'license-problem-gfdl-invariants', $name;
+                  }
+              }
+              if($line =~ m/the\s+Front-Cover\s+Texts\s+being/i) {
+                  if($line !~ m/the\s+Front-Cover\s+Texts\s+being\s+(?:<var>)?\s+list/) {
+                      tag 'license-problem-gfdl-invariants', $name;
+                  }
+              }
+          }
         }
         close $F or fail "can not close opened file $name: $!"
     }
diff --git a/checks/cruft.desc b/checks/cruft.desc
index 084354d..2ba0866 100644
--- a/checks/cruft.desc
+++ b/checks/cruft.desc
@@ -486,3 +486,9 @@ Info: The given source file is copyrighted under the non free
  license of json and the infamous clause:
  The Software shall be used for Good, not Evil.
 Ref: http://wiki.debian.org/qa.debian.org/jsonevil
+
+Tag: license-problem-gfdl-invariants
+Severity: serious
+Certainty: possible
+Info: The given source file contain is licensed under
+ GFDL with invariant section or frontcover.