Automatically scale SVGs to correct size

So the actual intrinsic size of the SVG now doesn't matter any more. Small SVGs will properly be upscaled without any interpolation necessary.
This can also improve performance, depending on the size you're displaying the zoomed image at. The original zoomed image was meant to be downscaled for all but the largest screens, so for all but the largest screens the performance should be a little better when there's SVGs involved.

contributing.md

@@ -55,6 +55,5 @@ Diagrams should be submitted in SVG format. Also for these there are a number of
 * Gradients are not supported.
 * Animations are not supported.
 * Patterns are not supported.
-* The image gets rendered by Qt at a fixed resolution matching the viewport of your image, and then scaled to the resolution that the user needs to display it at. For better quality, the SVG's viewport needs to be very large. Several thousand units is usually fine even for high DPI screens.
 
 It is up to the discretion of the package maintainer to decide whether images are too big or not. A major factor in this decision is whether the image is any bigger than strictly necessary.

resources/qml/ArticleImages.qml

@@ -79,8 +79,9 @@ GridLayout {
 					id: thumbnail
 					source: modelData.substring(0, modelData.indexOf("|"))
 					fillMode: Image.PreserveAspectFit
-					mipmap: true
 					anchors.fill: parent
+					sourceSize.width: width
+					sourceSize.height: height
 				}
 
 				Image {

resources/qml/SettingsGuide.qml

@@ -176,20 +176,33 @@ Window {
 			}
 
 			Rectangle {
-				width: zoom_image.paintedWidth
-				height: zoom_image.paintedHeight
+				width: zoom_image.visible ? zoom_image.paintedWidth : zoom_image_svg.paintedWidth
+				height: zoom_image.visible ? zoom_image.paintedHeight : zoom_image_svg.paintedWidth
 				color: "white" //Always white regardless of theme, to serve as background to the image.
 				anchors.centerIn: parent
 
 				AnimatedImage {
 					id: zoom_image
-					source: settingsGuideBase.zoomed_image
+					source: visible ? settingsGuideBase.zoomed_image : "" //Don't even try to render for SVG.
 					anchors.centerIn: parent
 					width: zoom_layer.width * 2 / 3
 					height: zoom_layer.height * 2 / 3
 					fillMode: Image.PreserveAspectFit
 					mipmap: true
 					onStatusChanged: playing = (status == AnimatedImage.Ready)
+					visible: settingsGuideBase.zoomed_image.split('.').pop() !== "svg" //Only for non-SVG.
+				}
+
+				Image { //Special one for SVG that automatically adjusts sourceSize. sourceSize is not supported for AnimatedImage, and AnimatedImage doesn't support animated SVG anyway.
+					id: zoom_image_svg
+					source: visible ? settingsGuideBase.zoomed_image : "" //Don't even try to render for non-SVG.
+					anchors.centerIn: parent
+					width: zoom_image.width
+					height: zoom_image.height
+					fillMode: Image.PreserveAspectFit
+					sourceSize.width: width
+					sourceSize.height: height
+					visible: !zoom_image.visible //Only for SVG.
 				}
 			}
 		}