Discard matches to single GPL word and other very short rules with mixed, non-matching case and/or in a binary an/or not on a single line and/or in giberish

[pombredanne]

gPL and similar is a source of noisy false positive. @AyanSinhaMahapatra what's your take there?

[AyanSinhaMahapatra]

Phillipe, yes uppercase/lowercase would be a good way to distinguish, and also binary, so having these as OR statements in the heuristics would be great, but I'll double check all the small license rules and check if this holds just to be sure.

[pombredanne]

There are also things to consider beyond the case such as:

• a bare word GPL/LGPL detection is found solo in a binary
• or is surrounded by gibberish (See also Improve gibberish license/copyright detection #2402 )
• or is surrounded by a context that makes it not a proper match

[pombredanne]

See also:

• Code wrongly detected as gpl-1.0 #2371
• C source code line mistaken for MPL licence  #2304
• high relevance for some very low character count rules find lots of GPL false positives #2484

[pombredanne]

See also #797

[pombredanne]

@chinyeungli FYI

[pombredanne]

Another case: "LICENSE.gpl.\n\n3." should not be detected as gpl-3.0_rdesc_1.RULE because of the two empty lines.