The pretty-print comparison already treats blank lines, comment-only lines
and preprocessor directives as ignorable, but only when scoring a single
diff entry: they still sat in the line collections handed to the aligner. A
run of #if/#else/#endif around a statement could then push the aligner into
matching an adjacent brace as inserted-and-deleted, failing a test whose
decompiled output was in fact correct. Drop those lines before diffing so
they cannot skew the alignment.
Assisted-by: Claude:claude-opus-4-8:Claude Code
Siegfried Pammer