Maciek,
I cannot duplicate your results exactly. However, doing what you describe
locks up gism for me.
Here is what I'm pretty sure is happening.
1. vector added twice (layers 1 & 2)
2. zoom to any region extents: d.vect is run producing PPM files for layers
1 & 2 that are composited using g.pnmcomp.
3. turn off layer 1 and zoom to any new region extents: active layer 2 is
re-rendered, but inactive layer 1 is not re-rendered because it is not
active (THIS is the problem. There was a check for this that apparently has
been lost in very recent changes).
4. make layer 1 active again and attempt to display: Layer 2 is correctly
rendered, but layer 1 is not rerendered. G.pnmcomp attempts to composite
layers 1 and 2, but they have different geometries causing it to hang (on my
system) or incorrectly display layer 1 (on your system).
We need to fix the bug in step 3. Thanks for finding it.
Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University
phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton
From: Maciek Sieczka <werchowyna@epf.pl>
Date: Sun, 7 May 2006 19:51:52 +0200
To: <grass-dev@grass.itc.it>
Cc: <cedricgrass@shockfamily.net>, <michael.barton@asu.edu>
Subject: gis.m: artifacts renderend
Hi,
I hope you don't hate me. Yet. 
There is a bug in gis.m that zooming, turning off and redisplaying
layers leads to artifacts:
1. add 2 vector layers - both the same vector
2. zoom to one of them [1]
3. turn off the 2nd one
4. zoom in [2]
5. turn on the 2nd one
6. redraw [3]
[1] whole_layer.png
[2] zoom.png
[3] dna.png
Maciek
