clean up trailing whitespace, add extensive tests for tag toggle

clean up trailing whitespace, add extensive tests for tag toggle

2000-10-03  Havoc Pennington  <hp@redhat.com>

	* gtk/testtextbuffer.c: clean up trailing whitespace,
	add extensive tests for tag toggle iteration.

	* gtk/gtktextiter.c (MAX_LINEAR_SCAN): decrease linear scan
	distance

	* gtk/gtktextbtree.c (gtk_text_line_next_could_contain_tag):
	optimize case where the tag root is on level 1
	(gtk_text_line_previous_could_contain_tag): attempt to implement
	(gtk_text_line_next_could_contain_tag): Abstract out node_compare
	functionality

	* gtk/gtktextiter.c (gtk_text_iter_backward_to_tag_toggle):
	Implement this, though not very efficiently.

	* gtk/gtktextiterprivate.h: reformat

	* gtk/gtktextiter.c (gtk_text_iter_get_char): return 0 on the end
	iterator

	* gtk/gtktextbuffer.c (gtk_text_buffer_delete_interactive): Fix
	this to properly revalidate the iterators.

	* gtk/gtktextview.c (gtk_text_view_delete): fix control-K to work
	properly at the end of the line (and therefore on empty lines)

	* gtk/gtktextbtree.c (gtk_text_btree_get_selection_bounds): Gee,
	maybe we should return a value...