The pathLength attribute description states that a negative value is an error, but does not give guidance on what to do with a value of zero.
https://svgwg.org/svg2-draft/paths.html#PathLengthAttribute
A value of zero should probably be an error too since the user agent scales all distance computations by the ratio of pathLength to the user agent's own calculated length.
A value of zero for pathLength would result in a ratio of zero (pathLength / calculated length).
According to my test, implementations handle a pathLength of zero differently.
FireFox = handles as an error (ignores, gives the same result as when a negative value is used)
Chrome = disables dash array
Safari = doesn't support pathLength (at least on dasharray)
InkScape = doesn't support pathLength (at least on dasharray)
The pathLength attribute description states that a negative value is an error, but does not give guidance on what to do with a value of zero.
https://svgwg.org/svg2-draft/paths.html#PathLengthAttribute
A value of zero should probably be an error too since the user agent scales all distance computations by the ratio of pathLength to the user agent's own calculated length.
A value of zero for pathLength would result in a ratio of zero (pathLength / calculated length).
According to my test, implementations handle a pathLength of zero differently.
FireFox = handles as an error (ignores, gives the same result as when a negative value is used)
Chrome = disables dash array
Safari = doesn't support pathLength (at least on dasharray)
InkScape = doesn't support pathLength (at least on dasharray)