[libc-commits] [libc] [libc] Treat -1 from fopencookie callbacks as an error (PR #236970)

[Michael Jones via libc-commits]

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@@ -41,20 +48,29 @@ class CookieFile : public LIBC_NAMESPACE::File {
         cookie(c), ops(cops) {}
 };
 
+// A callback reports failure by returning -1 and setting errno.
+int callback_error() { return libc_errno != 0 ? libc_errno : EIO; }
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michaelrj-google wrote:

why does this need to be a function if it's just one line? Also why is it reading `errno`? No internal function should set errno.

https://github.com/llvm/llvm-project/pull/236970