[librsvg: 1/2] Use specified width/height as inner SVG viewport by default

[Marge Bot <marge-bot src gnome org>]

commit b587892cf882e8bd0910b1ee7c570280fd1dad41
Author: Michael Howell <michael notriddle com>
Date:   Thu Oct 14 12:49:32 2021 -0700

    Use specified width/height as inner SVG viewport by default
    
    Fixes #788
    
    Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/607>

 src/structure.rs                                   |   8 ++++++--
 .../reftests/bugs/788-inner-svg-viewbox-ref.png    | Bin 0 -> 362 bytes
 .../reftests/bugs/788-inner-svg-viewbox.svg        |  21 +++++++++++++++++++++
 3 files changed, 27 insertions(+), 2 deletions(-)
---
diff --git a/src/structure.rs b/src/structure.rs
index 77cc49eb..3cc8ac46 100644
--- a/src/structure.rs
+++ b/src/structure.rs
@@ -208,7 +208,7 @@ impl Svg {
 
         let is_measuring_toplevel_svg = !has_parent && draw_ctx.is_measuring();
 
-        let (viewport, vbox) = if is_measuring_toplevel_svg || has_parent {
+        let (viewport, vbox) = if is_measuring_toplevel_svg {
             // We are obtaining the toplevel SVG's geometry.  This means, don't care about the
             // DrawingCtx's viewport, just use the SVG's intrinsic dimensions and see how far
             // it wants to extend.
@@ -216,7 +216,11 @@ impl Svg {
         } else {
             (
                 // The client's viewport overrides the toplevel's x/y/w/h viewport
-                draw_ctx.toplevel_viewport(),
+                if has_parent {
+                    svg_viewport
+                } else {
+                    draw_ctx.toplevel_viewport()
+                },
                 // Use our viewBox if available, or try to derive one from
                 // the intrinsic dimensions.
                 self.vbox.or_else(|| {
diff --git a/tests/fixtures/reftests/bugs/788-inner-svg-viewbox-ref.png 
b/tests/fixtures/reftests/bugs/788-inner-svg-viewbox-ref.png
new file mode 100644
index 00000000..93349f98
Binary files /dev/null and b/tests/fixtures/reftests/bugs/788-inner-svg-viewbox-ref.png differ
diff --git a/tests/fixtures/reftests/bugs/788-inner-svg-viewbox.svg 
b/tests/fixtures/reftests/bugs/788-inner-svg-viewbox.svg
new file mode 100644
index 00000000..25029f61
--- /dev/null
+++ b/tests/fixtures/reftests/bugs/788-inner-svg-viewbox.svg
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg"; fill="#FFFFFF" height="62px" version="1.1" viewBox="0 0 164 62" 
width="164px">
+       <defs>
+               <clipPath id="clip"><rect height="100%" width="100%" x="0" y="0"/></clipPath>
+       </defs>
+       <g clip-path="url(#clip)">
+               <g style="text-anchor:middle" transform="translate(72)">
+                       <linearGradient id="BOX" x1="100%" x2="100%" y1="100%" y2="0">
+                               <stop offset="0" style="stop-color:#2E2E2E"/>
+                               <stop offset="1" style="stop-color:#676769"/>
+                       </linearGradient>
+
+                       <g transform="translate(-148)">
+                               <svg height="45%" width="22px" x="100%" y="3.33%">
+                                       <rect fill="url(#BOX)" height="100%" width="100%"/>
+                                       <rect fill="green" x="50%" y="72%" width="4px" height="4px">3</rect>
+                               </svg>
+                       </g>
+               </g>
+       </g>
+</svg>