tree 7246f6b8d7f08b6088a88020db5976b22c18bd5d
parent e8c7cf207113d0a21485a2ba69fe872f3266cb51
author Benno Schulenberg <bensberg@justemail.net> 1484906295 +0100
committer Benno Schulenberg <bensberg@justemail.net> 1484914630 +0100

painting: do not let a match for 'end' overlap a match for 'start'

During precalculation and in step_two, we begin looking for an end
match only after the full start match, not merely one byte beyond
its starting point.  So do that too when searching backward for an
unpaired start match.

Also, index can never be zero here, because if the match was of length
zero, this piece of code will have been skipped by the preceding goto.
So we can always use REG_NOTBOL here.

(That goto is wrong, by the way: https://savannah.gnu.org/bugs/?50078,
but that will follow later.)