PS: Add three new public functions for emitting DSC comments.

This commit adds the following new functions to the cairo-ps API:

	cairo_ps_surface_dsc_comment
	cairo_ps_surface_dsc_begin_setup
	cairo_ps_surface_dsc_begin_page_setup

Many thanks are due to Michael Sweet who provided invaluble guidance
during the design of this API.

It is hoped that with this API in place, basically all printer control
that is likely to be desired to be performed with cairo PostScript
output is now possible.

This commit augments the ps-features test to exercise the new API.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/cairo-array.c b/src/cairo-array.c
index ed9538b0d..7252101b2 100644
--- a/src/cairo-array.c
+++ b/src/cairo-array.c
@@ -200,10 +200,8 @@ _cairo_array_index (cairo_array_t *array, int index)
      * which in the num_elements==0 case gets the NULL pointer here,
      * but never dereferences it.
      */
-    if (array->elements == NULL) {
-	assert (index == 0);
+    if (index == 0 && array->num_elements == 0)
 	return NULL;
-    }
 
     assert (0 <= index && index < array->num_elements);