Fixed-width spacing broken since a pango update in July 2019
Some time in July 2019, a pango update caused fixed-width spacing to break in gedit. This occurs 100% of the time in all versions of gedit I've tried (including the git tree) and is clear as day when using a font larger than Source Code Pro 10 (which is the default font for me). The specific font I prefer using and experience this issue with is Monospace Regular 12.
Here are screenshots demonstrating the issue:
The problem is clear to see by looking at the struct
keywords, which should be perfectly vertically aligned.
The pango developers don't know of any change they've made that could be responsible for this behavior. It should be noted that changing the tab width in gedit to any value—then back to the desired value—temporarily fixes the issue (e.g., if you have tab width set to 8 spaces by default when opening gedit, then change the tab width to 7 and then back to 8, the spacing issue will be fixed until gedit is restarted).
More info can be found in the pango issue I filed: pango#425 (closed)