On 11/9/20 9:34 AM, JIang Yuancheng wrote:
> grep -E “.*{10,}{10,}{10,}{10,}{10,}” can exhaust stack space then stack overflow comes out. (Tested on latest version 3.6)

This is a longstanding issue with the regex matcher. I installed the 
attached patch to document the issue better. Fortunately, the problem is 
mostly limited to contrived examples.