'm' units identifier not handled correctly

[Tavmjong Bah]

The 'm' units identifier along with 'ft' are not part of SVG and need special handling. The special handling for 'ft' seems to work but that for 'm' can lead to an incorrect 'viewBox'.

To reproduce:

1. Open an Inkscape with the default SVG file.
2. Open the XML dialog and observe the 'viewBox' attribute.
3. Open the Document Properties dialog to the 'Page' tab.
4. Change the Units in 'Custom Page Size' to 'm'
5. Change the Units back to the original units ('mm' in the case of trunk).

The 'viewBox' values will bo 100 times bigger than they should be.

Analysis:

The file units.xml should contain all the information needed to add new units to Inkscape. However, as 'm' and 'ft' are not part of SVG special handling is required. This special handling happens in two places: units.cpp for 'ft' and document.cpp for 'm' (setWidth(), setHeight()).

The need for special handling should be eliminated. As a quick fix, the special handling for 'm' should be moved to 'units.cpp'.

[su_v (suv-lp)]

See also comments for bug #1268355 wrt 'ft' and 'm' not part of SVG.

[su_v (suv-lp)]

Reproduced with trunk revision >= 13632 on OS X 10.7.5

[su_v (suv-lp)]

AFAICT does not affect 0.91.x (based on the 'steps to reproduce').

[Tavmjong Bah (tavmjong-free)]

Actually, 'ft' also occurs in svg-length.h and svg-length.cpp.

[Tavmjong Bah (tavmjong-free)]

#3: That is a good clue, as I had patched trunk with 13632 from trunk.

[Alvin Penner (apenner)]

fix committed to rev 13753
this fixes a bug in rev 13632

[Tavmjong Bah (tavmjong-free)]

Alvin, thanks for your prompt fix.

I have just checked in what I think is a better fix. That is moving the 'm' handling code from document.cpp to

  svg/svg-length.cpp
  svg/svg-length.h
  util/units.cpp

This is a more generic solution that follows the pattern from 'ft'.

See r13758

[su_v (suv-lp)]

@Tav - should this get backporting to the stable 0.91.x branch?

[Tavmjong Bah (tavmjong-free)]

@~suv: Probably yes, along with Alvin's accuracy fix.

[ScislaC (scislac)]

backported trunk commits r13753 & r13758 to 0.91.x r13661