Possible bug: identical lines added/removed in git diff

I think I'm running into a bug with git diff on v2.18.0. When I diff
the attached files, part of the diff ends up looking like:
...
 STARTCHAR U+00F0
 ENCODING 240
 SWIDTH 500 0
-DWIDTH 8 0
-BBX 7 12 1 0
-BITMAP
-12
-0C
-14
-22
-02
-3E
-42
-42
-82
-84
-84
-78
+DWIDTH 8 0
+BBX 8 12 0 0
+BITMAP
+1B
+0E
+1E
+33
+03
+3F
+63
+63
+C3
+C6
+C6
+7C
 ENDCHAR
 STARTCHAR U+00F1
...
where the "DWIDTH 8 0" and "BITMAP" lines are removed and added,
despite being identical. It only seems to be happening around this
section of the file, for the U+00F0 character. This also seems close
to a minimal reproduction of the issue. If I git add --patch and stage
a few hunks, then the duplicated lines seem to disappear.

Steps to reproduce: git diff --no-index unitera_bold_italic.bdf.old unitera_bold_italic.bdf.new (It also happens inside a repo, this just seemed the easiest way to demonstrate.)

Gabriel Holodak