No error message writing invalid values to PNG:PixelsPerUnitX/Y

[StarGeek]

Writing invalid values to the PNG PixelsPerUnitX/Y tags does return an error message, where other numeric tags will return a message of Not a integer/floating point number for

Example

Code Select Expand

C:\>exiftool -P -overwrite_original -PNG:PixelsPerUnitX=junk -PNG:PixelsPerUnitY=junk Y:\!temp\Test4.png
    0 image files updated
    1 image files unchanged
I thought I should bring this up, though it's probably not high priority.

[Phil Harvey]

Great, thanks.  An easy fix that will appear in 13.09.  I also added an automated test for a missing check like this and found another table in the Jpeg2000 code with this issue.

- Phil