new symbology line decoration has wrong orientation when final vertices are duplicated

[strk]

After a long time happyness due to closing ticket #3434 the wrong arrow orientation bug is back.

This time the problem is due to lines having duplicated vertices toward the end, so that the "last segment" is empty.

I hit this bug while testing handling of such cases by postgis topology so it was intentional to have lines with endings collapsed. Example:

LINESTRING(10 0, 0 0, 0 0)

I haven't checked this specific case but what I'm looking at right now is an arrow pointing o the right, so I guess you'd see the same right-pointing arrow for the case above (which is instead going to the left). Note that the same right-arrow should appear for any line orientation: vertical or diagonal...

Label orientation might be affected too, but didn't try to produce that bug (I guess it'd take making it so that centroid of the line falls on a collapsed segment)

[strk]

The following changes since commit f88f72172450df32a41588b5b14915c69ae79c90:
  Marco Hugentobler (1):
        Discard empty http parameters in mapserver

are available in the git repository at:

  git://github.com/strk/Quantum-GIS.git bug3837

Sandro Santilli (1):
      Fix wrong arrow orientation when lines end with duplicated points (#3837)

 src/core/symbology-ng/qgslinesymbollayerv2.cpp |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

[strk]

One way to pull those changes is:

$ git remote add strk git://github.com/strk/Quantum-GIS.git
$ git pull strk bug3837

Oh, my bug3837 is branched from master, not 1_7_0 branch

[strk]

Note that the change was tested with vertical, horizontal and diagonal lines. Was also tested with lines collapsed to a point, in which case no arrow is printed.

[jef]

applied in commit ef981f19a3e0676a2e0b78412eadf213794b7eb1