Regex Debugger: show wrong steps for failed atomic group / possessive quantifiers

[liudongmiao]

Bug Description

For non-matched "atomic group", "regex debugger" show wrongs steps.

Reproduction steps

For atomic group:

• Regex: ^(?>a+)$
• Input: aaaaaaaaaab
• PCRE2: show no match, 5 steps
• Debugger: show no match, 16 steps
• Demo: https://regex101.com/r/1tlLsi/1

For possessive quantifiers:

• Regex: ^a++$
• Input: aaaaaaaaaab
• PCRE2: show no match, 3 steps
• Debugger: show no match, 14 steps
• Demo: https://regex101.com/r/1tlLsi/2

Expected Outcome

Debugger show the same steps as PCRE2.

Browser

N/A

OS

N/A

[firasdib]

This is because the debugger disables some of the native optimizations in the engine, in order to produce the information it does. You should not read into the step counts too much