Wrong GPL version detection due to rule gpl_35.RULE

[Toniprni]

Description

Due to ScanCode's rule gpl_35.RULE, a clear GPL-3.0-or-later hit was marked as GPL-1.0-or-later with a high license score 98.08. This also happened in other files. See the ScanCode results for the file below.

    {
        "path": "bc-1.07.1.tar.gz-extract/bc-1.07.1/bc/storage.c",
        "type": "file",
        "name": "storage.c",
        "base_name": "storage",
        "extension": ".c",
        "size": 22842,
        "date": "2017-04-07",
        "sha1": "e583fcf6e057c894e1ed820d5a78603f197374c0",
        "md5": "2a5785494bfb7e97194f05810c19656a",
        "mime_type": "text/x-c",
        "file_type": "C source, ASCII text",
        "programming_language": "C++",
        "is_binary": false,
        "is_text": true,
        "is_archive": false,
        "is_media": false,
        "is_source": true,
        "is_script": false,
        "licenses": [
            {
                "key": "gpl-1.0-plus",
                "score": 98.08,
                "name": "GNU General Public License 1.0 or later",
                "short_name": "GPL 1.0 or later",
                "category": "Copyleft",
                "is_exception": false,
                "owner": "Free Software Foundation (FSF)",
                "homepage_url": "http://www.gnu.org/licenses/old-licenses/gpl-1.0-standalone.html",
                "text_url": "http://www.gnu.org/licenses/old-licenses/gpl-1.0-standalone.html",
                "reference_url": "https://enterprise.dejacode.com/urn/urn:dje:license:gpl-1.0-plus",
                "spdx_license_key": "GPL-1.0-or-later",
                "spdx_url": "https://spdx.org/licenses/GPL-1.0-or-later",
                "start_line": 5,
                "end_line": 17,
                "matched_rule": {
                    "identifier": "gpl_35.RULE",
                    "license_expression": "gpl-1.0-plus",
                    "licenses": [
                        "gpl-1.0-plus"
                    ],
                    "is_license_text": false,
                    "is_license_notice": true,
                    "is_license_reference": false,
                    "is_license_tag": false,
                    "matcher": "3-seq",
                    "rule_length": 104,
                    "matched_length": 102,
                    "match_coverage": 98.08,
                    "rule_relevance": 100
                }
            }
        ],

How To Reproduce

Scan the following:
bc-1.07.1.tar.gz

File path: bc-1.07.1.tar.gz-extract/bc-1.07.1/bc/storage.c

Gives result => GPL-1.0-or-later and uses rule gpl_35.RULE

System configuration

• What OS are you running on? (Windows Subsystem For Linux (Ubuntu 18.04))
• What version of scancode-toolkit was used to generate the scan file? Version 3.1.1 AND develop branch (both produce the same issue)
• What installation method was used to install/run scancode? (source download)

[pombredanne]

@Toniprni Thank you ++ for this report! that's a great catch!

FYI, If you run with these extra options it help see what the problem is:

• --license-text see the actual license text detected
• --license-text-diagnostics with the above, in the matched license text, include diagnostic highlighting with surrounding square brackets [] the words that are not matched.

See for instance: bc.json.txt
There are a few extra issues there that should be easy to fix with a few updated and new license detection rules.

[pombredanne]

This has been fixed and merged in develop