[clang-tools-extra] [clangd] Fix SIGSEGV crash when receiving a textDocument/didOpen request with the URI pointing to a directory (PR #177834)

[Nathan Ridge via cfe-commits]

https://github.com/HighCommander4 commented:

It's not clear me to yet that individual LSP requests are the best place to have this check.

(For example, what makes `textDocument/documentSymbol` different from `textDocument/definition` that one needs this check and the other doesn't?)

Were you able to reproduce the crash locally in a debug build? Can you post a crash stacktrace from the debug build, so we can better understand what exactly is crashing and why?

https://github.com/llvm/llvm-project/pull/177834