Do not find erroneus literals when there is a capture group and a character class of five or more

[PeterSP]

What version of ripgrep are you using?

ripgrep 0.10.0
-SIMD -AVX (compiled)
+SIMD +AVX (runtime)

How did you install ripgrep?

I used cargo install

What operating system are you using ripgrep on?

Darwin C02TM0LHG8WL 17.7.0 Darwin Kernel Version 17.7.0: Thu Jun 21 22:53:14 PDT 2018; root:xnu-4570.71.2~1/RELEASE_X86_64 x86_64

If this is a bug, what is the actual behavior?

$ echo " a_" | rg ' ([abcde]+_)' --debug
DEBUG|grep_regex::literal|${HOME}/.cargo/registry/src/github.jpy.wang-1ecc6299db9ec823/grep-regex-0.1.1/src/literal.rs:110: required literal found: " _"
DEBUG|globset|${HOME}/.cargo/registry/src/github.jpy.wang-1ecc6299db9ec823/globset-0.4.2/src/lib.rs:429: built glob set; 0 literals, 0 basenames, 8 extensions, 0 prefixes, 0 suffixes, 0 required extensions, 0 regexes
$ echo " a_" | rg ' ([abcd]+_)' --debug
DEBUG|grep_regex::literal|${HOME}/.cargo/registry/src/github.jpy.wang-1ecc6299db9ec823/grep-regex-0.1.1/src/literal.rs:100: required literals found: [Cut( a), Cut( b), Cut( c), Cut( d), Complete( _)]
DEBUG|globset|${HOME}/.cargo/registry/src/github.jpy.wang-1ecc6299db9ec823/globset-0.4.2/src/lib.rs:429: built glob set; 0 literals, 0 basenames, 8 extensions, 0 prefixes, 0 suffixes, 0 required extensions, 0 regexes
 a_

Or, without all that noise:

$ echo " a_" | rg ' ([abcde]+_)'
$ echo " a_" | rg ' ([abcd]+_)'
 a_

If this is a bug, what is the expected behavior?

What do you think ripgrep should have done?

1. Not find " _" as a literal which neither matches all nor any of the strings the pattern desired matches.
2. Find " a_" as a match.

[lespea]

Looks like the same issues as #1081. I tested the version of ripgrep with this fixed and it appears to work as expected.

$  echo " a_" | rg ' ([abcde]+_)'; echo " a_" | rg ' ([abcd]+_)'
a_
a_

[PeterSP]

It appears that this is a dupe of #1064 (in that it's fixed by the associated change).

$ cargo uninstall ripgrep
$ cargo install ripgrep --git [email protected]:BurntSushi/ripgrep.git
...
$ echo "abg" | rg 'a([bcdef]+g)' --debug
DEBUG|grep_regex::literal|grep-regex/src/literal.rs:110: required literal found: "a"
DEBUG|globset|globset/src/lib.rs:429: built glob set; 0 literals, 0 basenames, 8 extensions, 0 prefixes, 0 suffixes, 0 required extensions, 0 regexes
abg

[PeterSP]

I can still add a regression test for this, but I suspect it's not worth it (as it's nearly identical to the regression test for #1064).

[BurntSushi]

Yeah, I think we are all set here. Thanks for the report!