[checkoutlinesUFO] glyph file names might not correspond to existing file names …

[frankrolf]

… resulting in overlaps not being removed in the OTF file.

The attached UFO file (c/o @rbmntjs) has a singe AE glyph, drawn with overlaps.
Nevertheless, it does not make it through the FDK workflow, and I have finally found out why:

Consider the following steps:

① remove overlap

$ checkoutlinesufo -e SerifText-Bold.ufo
AE There is an overlap.Done with font

checkoutlinesufo recoginzes the overlap – great!

② generate OTF

$ makeotf -f SerifText-Bold.ufo/
makeotf [Warning] Could not find default features file at 'None'. Font will be built without any layout features.
makeotfexe [NOTE] Adding glyph .notdef, SID 0.
Built development mode font 'SerifText-Bold.otf'.

③ convert back to UFO

$ tx -ufo -o SerifText-Bold_roundtrip.ufo SerifText-Bold.otf

The new UFO still has the overlaps in it, which means they are present in the OTF as well.
By coincidence I found out the reason for this is the glyphname-to-filename writer in checkoutlinesufo.

This is the original file tree of the UFO file:

SerifText-Bold.ufo:
	fontinfo.plist
	glyphs:
		AE_.glif
		contents.plist
	layercontents.plist
	lib.plist
	metainfo.plist

Here is how it looks after running checkoutlinesufo:

SerifText-Bold.ufo:
	data:
		com.adobe.type.processedHashMap
	fontinfo.plist
	glyphs:
		AE_.glif
		contents.plist
	glyphs.com.adobe.type.processedglyphs:
		A_E_.glif
		contents.plist
	layercontents.plist
	lib.plist
	metainfo.plist

As is obvious, A_E_.glif is not equivalent to AE_.glif, which is why makeotf does not recognize them as equivalent. When I rename the latter to A_E_.glif (and re-wire in contents.plist), everything works as expected.

I suggest for makeotf to compare the glif files through the contents.plist rather than their file names.
An intermediate solution for Robin might be normalizing the UFO file before running checkoutlinesUFO.

SerifText-Bold.ufo.zip

[miguelsousa]

I suggest for makeotf to compare the glif files through the contents.plist rather than their file names.

Agree. Looking into it.

[miguelsousa]

The failure to produce a font (via makeotf) without overlaps is caused by tx. I opened #740 specifically to address it.

[miguelsousa]

AFAICT checkoutlinesUFO is not doing anything wrong; the GLIF files it writes in glyphs.com.adobe.type.processedglyphs have a normalized filename, but that's a good thing, I think.
I'll leave this issue open until #740 is fixed.

[miguelsousa]

The bug in tx (#740) is fixed. Also added a makeotf test.