perf: Guarantee path width is non-negative

This quells the following warning:

  perf/micro/hatching.c:39:5: warning: cannot optimize loop, the
  loop counter may overflow

Width and height aren't going to be negative so enforce it so that the
compiler can do whatever optimization it wants to do.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
test: Quell warning for inclusion of old rsvg header files

This silences a warning due to header file deprecated as of libsrvg
2.36.2.  Tested and verified this hackaround on librsvg 2.36.4 and
2.36.1.  No need to change version dependencies.

  In file included from test/any2ppm.c:73:0:
  /usr/include/librsvg-2.0/librsvg/rsvg-cairo.h:27:2: warning:
  #warning "Including <librsvg/rsvg-cairo.h> directly is deprecated."

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
test: Quell warning for deprecated g_type_init()

The g_type_init() routine was deprecated in glib 2.34.  Tested and
verified this conditionalization on glib 2.32 and 2.36.  No need to
change version dependencies.

  test/any2ppm.c:864:5: warning: ‘g_type_init’ is deprecated
  (declared at /usr/include/glib-2.0/gobject/gtype.h:669)

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
xml: Drop unused variable

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
xml: constify source objects for emit routines

This quells the following warnings:

  src/cairo-xml-surface.c:576:5: warning: passing argument 2 of
  ‘_cairo_xml_surface_emit_clip_boxes’ discards ‘const’ qualifier from
  pointer target type
  src/cairo-xml-surface.c:462:1: note: expected ‘struct cairo_clip_t
  *’ but argument is of type ‘const struct cairo_clip_t *’

Most of the cairo_xml*emit* routines const their source objects;
these should follow suit.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
mesh: Avoid theoretical infinite loops

This quells this warning:

  src/cairo-mesh-pattern-rasterizer.c:731:5: warning: cannot
  optimize possibly infinite loops

I guess the compiler's complaining because if vsteps were negative or
equal to UINT_MAX the loop could cycle infinitely.  Silly compiler.

Fix as suggested by Chris Wilson <chris@chris-wilson.co.uk>
gl: Handle PIXMAN_a8r8g8b8_sRGB format in switch

Fixes the following compiler warning:

  cairo-gl-surface.c:182:5: warning: enumeration value
  ‘PIXMAN_a8r8g8b8_sRGB’ not handled in switch

Same fix as done for image in 1d0055078.

Chris Wilson <chris@chris-wilson.co.uk>
image: Fix bad HTML generation in code docs for cairo-format-stride-for-width

Patch from Simon Kågedal Reimer

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63257
Add explanation to enum _cairo_int_status

Patch based on suggestion by Homer Hsing

Bugzilla:  https://bugs.freedesktop.org/show_bug.cgi?id=50416
Add explanation to _cairo_surface_create_in_error

Patch by Homer Hsing

Bugzilla:  https://bugs.freedesktop.org/show_bug.cgi?id=50413
Add comment to explain _cairo_edge_compute_intersection_*

Patch by Homer Hsing

Bugzilla:  https://bugs.freedesktop.org/show_bug.cgi?id=50412
Correct spelling of "tessellator" throughout code

Based on patch suggested by Homer Hsing

Bugzilla:  https://bugs.freedesktop.org/show_bug.cgi?id=50411
xlib: Fix typo in documentation
image: Add NULL checks for return value of _pixman_image_for_color()

This fixes crash in pixman_image_composite32().

Originally fixed by Yoshitaro Makise.

Reviewed-by: Bryce Harrington <b.harrington@samsung.com>
Signed-off-by: Bryce Harrington <b.harrington@samsung.com>
Merge branch 'master' of git://anongit.freedesktop.org/git/cairo