[PATCH] D37491: [Preamble] Fixed preamble breaking with BOM presence (and particularly, fluctuating BOM presence)

[Ilya Biryukov via Phabricator via cfe-commits]

ilya-biryukov added a comment.

In https://reviews.llvm.org/D37491#864649, @erikjv wrote:

> Will this fix PR25023 and PR21144?


PR25023 <https://bugs.llvm.org/show_bug.cgi?id=25023> should be fixed by this change. It is essentially a repro of the same bug.
Could we add a `c-index-test`-based test here to make sure we addressed that particular use-case?

The state of PR21144 <https://bugs.llvm.org/show_bug.cgi?id=21144>  won't be affected, as this change does not touch the code invoked during normal compilation without preambles.
If PR21144 <https://bugs.llvm.org/show_bug.cgi?id=21144> is fixed in a way that would make `SourceLocation`s the same regardless if BOM was present or not, we might have a better guarantee that nothing will break in case we want to reuse preamble between BOM/non-BOM versions.


https://reviews.llvm.org/D37491