Squid 4.2 已发布，版本更新内容如下：
4.2 (#272)
Fixed build on FreeBSD v11.2 (#266)
Optimization: Faster response headers packing (#230)
Bug #4870: milliseconds logformats prepend 0s instead of spaces (#255)
Source Format Enforcement
Fix %>ru logging of huge URLs (#259)
Bug #4843 pt3: GCC-8 fixes and refactoring (#172) (#256)
Restored support for the https_port clientca option (#252)
Prep for 3.5.28 (#251)
Source Format Enforcement
Do not assign nil values in ACLFilledChecklist::syncAle() (#240)
Optimization: Fewer epoll(2) system calls when closing a socket (#235)
Documented when helper requests get queued (#238)
Fix segmentation fault on -k parse (#218)
Bug #4861: HTTPMSGLOCK missing pointer safety (#228)
Bug #4861: HTTPMSGLOCK missing pointer safety (#228)
Maintenance: Fix mkrelease.sh script (#237)
可以看到，主要是修复了 bug，以及进行一些优化。