ag matches blank lines with pattern '\s*'

[d-c-d]

at matched the blank line even though the literal q was part of the pattern
This happened on cygwin ( not significant as it happens on Linux also appended below)
cloned and compiled from source
Minor patch to get it to compile on cygwin ( see below )

This was reduced from a more realistic pattern, but ag should not match and print the blank line, just the line with the q
Tried with a '.*' prefix, ' *' ( zero or more spaces ) and no prefix - those all work
I had started by anchoring to the beginning of the line - ( e.g. '^\s+q' but it's broken in that case also )

$  ( echo "" ; echo q  ) > q && ./ag  '\s*q' q
1:
2:q



$ ./ag --version
ag version 2.2.0

Features:
  +jit +lzma +zlib


expected just one line to print

$ perl -nle 'print if /^\s*q/' q
q

$ grep -P '^\s*q' q
q


$  ( echo "" ; echo q  ) > q && ack  '\s*q' q
q

$ ag --version
ag version 2.1.0

Features:
  +jit +lzma +zlib

$ ack --version
ack 2.22
Running under Perl 5.30.3 at /usr/bin/perl.exe

Copyright 2005-2017 Andy Lester.

This program is free software.  You may modify or distribute it
under the terms of the Artistic License v2.0.

diff --git a/src/main.c b/src/main.c
index e116f70..763cb51 100644
--- a/src/main.c
+++ b/src/main.c
@@ -154,7 +154,7 @@ int main(int argc, char **argv) {
             }
 #if defined(HAVE_PTHREAD_SETAFFINITY_NP) && (defined(USE_CPU_SET) || defined(HAVE_SYS_CPUSET_H))
             if (opts.use_thread_affinity) {
-#if defined(__linux__) || defined(__midipix__)
+#if defined(__CYGWIN__) || defined(__linux__) || defined(__midipix__)
                 cpu_set_t cpu_set;
 #elif __FreeBSD__
                 cpuset_t cpu_set;




dcd@jetson:~$ ag --version
ag version 2.1.0

Features:
  +jit +lzma +zlib
dcd@jetson:~$ ( echo "" ; echo q  ) > q && ag -i '\s*q' q
1:
2:q
dcd@jetson:~$ uname -a
Linux jetson 4.9.140-tegra #1 SMP PREEMPT Wed Mar 13 00:32:22 PDT 2019 aarch64 aarch64 aarch64 GNU/Linux

[kraxli]

I face similar problems. A solution to your issue may be to apply a look-ahead before your pattern:

(?=\S+)