Open Radar

 
Summary:
It appears that Xcode 9 has changed the way indentation of Tab chars is calculated, leading to out-of-alignment formatting of lots of code.

Steps to Reproduce:
Open the attached text in both Xcode 9b3 and 8. Note that "attrlist_t" and "fssearchblock_t" are supposed to be vertically aligned. In Xcode 8 they are, in Xcode 9, they are not.

Expected Results:
correct alignment

Observed Results:
incorrect alignment

Version:
Version 9.0 beta 3 (9M174d)


Attached text for demonstration:

// The identifiers (attrlist_t, fssearchblock_t) should be indented at the same position on screen, provided TAB width is set to 4 spaces,
// and using a fixed-width font (e.g. Menlo 11).
// That's happening in BBEdit as well as in Xcode 8 and every other common programming editor I did try.
// However, Xcode 9b3 indents these incorrectly, shifting the fssearchblock_t to the left, requiring ANOTHER Tab char to align it with attrlist_t.
// That's not good as it would mess up any such indentation suddenly for practically all existing code.

;	;	;	;	;	;	;	;	;
typedef struct attrlist			attrlist_t;
typedef struct fssearchblock	fssearchblock_t;


Resolution from ADR:

Issue the following Terminal cmd:

defaults write com.apple.dt.Xcode NSFontDefaultScreenFontSubstitutionEnabled NO