[clang] [clang][Sema] Null-check type in resolveMemberExpr() before checking for auto type (PR #124628)

[Nathan Ridge via cfe-commits]

HighCommander4 wrote:

No test case because there wasn't one in the bug report; I diagnosed the issue based on the stack trace only.

https://github.com/llvm/llvm-project/pull/124628