[Plplot-devel] [Bug] Plmap omits lines at the left hand side of the map

[Mark de W. <m.d...@da...>]

Hi,

Recently I ran into an issue with the plplot 5.11.1 on Windows. The 
plmap code seems to omit lines entirely when a part of the line is not 
visible. This only occurs when the line is not visible on the left hand 
side of the plot. When a part is not visible on the right hand side it 
is properly shown.

At my Debian Stable system I use the system's 5.10.0 version. There the 
issue doesn't occur. (I noticed the plmap code has been rewritten 
between 5.10.0 and 5.11.0.) I also tested the bug on Debian Stable with 
5.11.1 and a recent master [d71e48], both have the issue.

Attached a modified example 19 where the bug is shown. The first plot 
shows the entire coast of Ireland. The second plot should only omit a 
small part of the coast, but instead the entire coast has been removed. 
Only the internal border of Ireland remains visible. This seems to 
happen with all coast lines; I picked Ireland since it shows the bug nicely.


Regards,
Mark de Wever

PS: It seems the old deprecated plmap code no longer shows a map (at 
least on Windows). I didn't investigate further, I just installed the 
shapelib library.

PPS: There also seems to be another issue with a filled polygon map, but 
I'm still investigating. If it really is an issue, I'll report it.