fix(ext/ffi): Empty buffers error with index out of bounds on FFI #14997
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Fixes #14993.
So, it turns out sometimes people create empty buffers and use them as FFI parameters. These sorts of pointers are absolutely not for writing or reading from (doing so is UB in at least C++ and LLVM), but they can serve a useful function as "end of buffer" pointers.
One way or another, these must not crash Deno.