uvcalc_lightmap would raise an error on meshes with no faces.

auto-threads wasnt working for baking.

release/scripts/uvcalc_lightmap.py

@@ -517,7 +517,7 @@ def main():
 	
 	if not Draw.PupBlock('Lightmap Pack', [\
 	'Context...',
-	('Active Object', PREF_ACT_ONLY, 'If disabled, use all objects for packing the lightmap.'),\
+	('Active Object', PREF_ACT_ONLY, 'If disabled, include other selected objects for packing the lightmap.'),\
 	('Selected Faces', PREF_SEL_ONLY, 'Use only selected faces from all selected meshes.'),\
 	'Image & UVs...',
 	('Share Tex Space', PREF_PACK_IN_ONE, 'Objects Share texture space, map all objects into 1 uvmap'),\
@@ -538,7 +538,7 @@ def main():
 			return
 		meshes = [ ob.getData(mesh=1) ]
 	else:
-		meshes = dict([ (me.name, me) for ob in scn.objects.context for me in (ob.getData(mesh=1),) if not me.lib])
+		meshes = dict([ (me.name, me) for ob in scn.objects.context for me in (ob.getData(mesh=1),) if not me.lib if len(me.faces)])
 		meshes = meshes.values()
 		if not meshes:
 			Draw.PupMenu('Error%t|No mesh objects selected.')

source/blender/render/extern/include/RE_pipeline.h

@@ -177,6 +177,9 @@ void RE_DataBase_ApplyWindow(struct Render *re);
 /* override the scene setting for amount threads, commandline */
 void RE_set_max_threads(int threads);
 
+/* set the render threads based on the commandline and autothreads setting */
+void RE_init_threadcount(Render *re);
+
 /* the main processor, assumes all was set OK! */
 void RE_TileProcessor(struct Render *re, int firsttile, int threaded);
 

source/blender/render/intern/source/convertblender.c

@@ -5417,6 +5417,9 @@ void RE_Database_Baking(Render *re, Scene *scene, int type, Object *actob)
 
 	/* renderdata setup and exceptions */
 	re->r= scene->r;
+	
+	RE_init_threadcount(re);
+	
 	re->flag |= R_GLOB_NOPUNOFLIP;
 	re->excludeob= actob;
 	if(type == RE_BAKE_LIGHT)

source/blender/render/intern/source/pipeline.c

@@ -2675,3 +2675,12 @@ void RE_set_max_threads(int threads)
 		printf("Error, threads has to be in range 1-%d\n", BLENDER_MAX_THREADS);
 	}
 }
+
+void RE_init_threadcount(Render *re) 
+{
+	if ((re->r.mode & R_FIXED_THREADS)==0 || commandline_threads == 0) { /* Automatic threads */
+		re->r.threads = BLI_system_thread_count();
+	} else if(commandline_threads >= 1 && commandline_threads<=BLENDER_MAX_THREADS) {
+		re->r.threads= commandline_threads;
+	}
+}