fix cmap table selection (fix #649)

[Connum]

Description

I introduced a bug with my PR #338, this is the fix for it. We always want to take the first CMAP table that we support, but keep on looking for an optional format 14 table that will be applied separately (this is the only exception, all other CMAP tables are exclusive). But I forgot to check if we already found a CMAP table when setting the offset for the supported table format, so it kept overriding the selected table until it found a format 14 table, thus always using the last instead of the first supported table.

Motivation and Context

fix #649, this bug broke the unicode test suite tests CFF-1 and CFF-2, and probably other fonts as well.

How Has This Been Tested?

loaded the FDArray test fonts and checked if the chars that broke in the test suite are displayed as expected

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I did npm run test and all tests passed green (including code styling checks).
• I have added tests to cover my changes.
• My change requires a change to the documentation.
• I have updated the README accordingly.
• I have read the CONTRIBUTING document.