Hope it can be solved. Font file error, throw an exception or skip

[givetimetolife]

When I use a font file to write PDF, when the file contains unsupported characters. Expect to return an obvious error instead of an error "jung-kurt/gofpdf/fpdf.go:2789". Or you can skip unsupported data，Continue to write。

location:
jung-kurt/gofpdf/fpdf.go:2789 ==》 l += float64(cw[int(c)])

error:
panic: runtime error: index out of range [127775] with length 65536 [recovered]
panic: runtime error: index out of range [127775] with length 65536

[jung-kurt]

This is related to a shortcoming discussed in #255. The contributor of the UTF-8 code has not made any comments about this.

Or you can skip unsupported data，Continue to write

I think this is the most practical expedient at this point.

[jung-kurt]

#337 fixes this when it occurs within a call to MultiCell(). An error will be returned in the case of an out-of-range rune. Errors can be handled as described in the documentaiton.