From 84eae855ee57ab1c37c8a84ad7e7afcd40b919e6 Mon Sep 17 00:00:00 2001
From: Eirik Aavitsland <eirik.aavitsland@theqtcompany.com>
Date: Wed, 18 Nov 2015 16:58:45 +0100
Subject: Improve format detection in the image reader plugin

canRead() would reject a file starting with an xml comment.

canRead() by design accepts anything that looks like the start of an
xml file, and the comment token "<!--" should be an indicator as good
as any of an xml file.

Task-number: QTBUG-49496
Change-Id: Id3c17f6b02344fa6a20bc2a839e345e5cebc14c2
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
---
 src/plugins/imageformats/svg/qsvgiohandler.cpp |  4 ++--
 tests/auto/qicon_svg/icons/triangle.svg        | 12 ++++++++++++
 tests/auto/qicon_svg/tst_qicon_svg.cpp         |  1 +
 3 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 tests/auto/qicon_svg/icons/triangle.svg

diff --git a/src/plugins/imageformats/svg/qsvgiohandler.cpp b/src/plugins/imageformats/svg/qsvgiohandler.cpp
index 8790796..8a9cbb2 100644
--- a/src/plugins/imageformats/svg/qsvgiohandler.cpp
+++ b/src/plugins/imageformats/svg/qsvgiohandler.cpp
@@ -122,7 +122,7 @@ bool QSvgIOHandler::canRead() const
     if (buf.startsWith("\x1f\x8b")) {
         setFormat("svgz");
         return true;
-    } else if (buf.contains("<?xml") || buf.contains("<svg")) {
+    } else if (buf.contains("<?xml") || buf.contains("<svg") || buf.contains("<!--")) {
         setFormat("svg");
         return true;
     }
@@ -251,7 +251,7 @@ bool QSvgIOHandler::supportsOption(ImageOption option) const
 bool QSvgIOHandler::canRead(QIODevice *device)
 {
     QByteArray buf = device->peek(8);
-    return buf.startsWith("\x1f\x8b") || buf.contains("<?xml") || buf.contains("<svg");
+    return buf.startsWith("\x1f\x8b") || buf.contains("<?xml") || buf.contains("<svg") || buf.contains("<!--");
 }
 
 QT_END_NAMESPACE
diff --git a/tests/auto/qicon_svg/icons/triangle.svg b/tests/auto/qicon_svg/icons/triangle.svg
new file mode 100644
index 0000000..e858490
--- /dev/null
+++ b/tests/auto/qicon_svg/icons/triangle.svg
@@ -0,0 +1,12 @@
+<!-- Generator: Adobe Illustrator 19.1.0, SVG Export Plug-In  -->
+<svg version="1.1"
+     xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:a="http://ns.adobe.com/AdobeSVGViewerExtensions/3.0/"
+     x="0px" y="0px" width="39.2px" height="39.2px" viewBox="0 0 39.2 39.2" style="enable-background:new 0 0 39.2 39.2;"
+     xml:space="preserve">
+<style type="text/css">
+    .st1{fill:#1B1E23;}
+</style>
+<defs>
+</defs>
+<polygon class="st1" points="15.3,11.3 29.2,19.6 15.3,27.9 "/>
+</svg>
diff --git a/tests/auto/qicon_svg/tst_qicon_svg.cpp b/tests/auto/qicon_svg/tst_qicon_svg.cpp
index f5b97e0..893cf99 100644
--- a/tests/auto/qicon_svg/tst_qicon_svg.cpp
+++ b/tests/auto/qicon_svg/tst_qicon_svg.cpp
@@ -60,6 +60,7 @@ void tst_QIcon_Svg::initTestCase()
         QFAIL("Can't find images directory!");
     if (!QImageReader::supportedImageFormats().contains("svg"))
         QFAIL("SVG support is not available");
+    QCOMPARE(QImageReader::imageFormat(prefix + "triangle.svg"), QByteArray("svg"));
 }
 
 void tst_QIcon_Svg::svgActualSize()
-- 
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