From b696d6dbfb8453948010ed786d9ab24bd3d1b485 Mon Sep 17 00:00:00 2001
From: Michael Weghorn <m.weghorn@posteo.de>
Date: Wed, 9 Sep 2020 13:52:30 +0200
Subject: [PATCH] Support '#page=<pagenum>' fragment to open at page <pagenum>

Support the '#page=<pagenum>' fragment to specify which page
to open the document at, in addition to the existing '#<pagenum>'
syntax.

For PDF, the '#page=<pagenum>' fragment is specified in RFC 8118,
section 3.

BUG: 406831
---
 autotests/parttest.cpp | 21 +++++++++++++++++++++
 part.cpp               | 12 +++++++++++-
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/autotests/parttest.cpp b/autotests/parttest.cpp
index f3e489b92..bcfdb3ff6 100644
--- a/autotests/parttest.cpp
+++ b/autotests/parttest.cpp
@@ -95,6 +95,7 @@ private slots:
     void testAdditionalActionTriggers();
     void testTypewriterAnnotTool();
     void testJumpToPage();
+    void testOpenAtPage();
     void testForwardBackwardNavigation();
     void testTabletProximityBehavior();
     void testOpenPrintPreview();
@@ -1794,6 +1795,26 @@ void PartTest::testJumpToPage()
     QCOMPARE(part.m_pageView->verticalScrollBar()->value(), pageWithSpaceTop - 4);
 }
 
+void PartTest::testOpenAtPage()
+{
+    const QString testFile = QStringLiteral(KDESRCDIR "data/simple-multipage.pdf");
+    QUrl url = QUrl::fromLocalFile(testFile);
+    Okular::Part part(nullptr, nullptr, QVariantList());
+
+    const uint targetPageNumA = 25;
+    const uint expectedPageA = targetPageNumA - 1;
+    url.setFragment(QString::number(targetPageNumA));
+    part.openUrl(url);
+    QCOMPARE(part.m_document->currentPage(), expectedPageA);
+
+    // 'page=<pagenum>' param as specified in RFC 3778
+    const uint targetPageNumB = 15;
+    const uint expectedPageB = targetPageNumB - 1;
+    url.setFragment("page=" + QString::number(targetPageNumB));
+    part.openUrl(url);
+    QCOMPARE(part.m_document->currentPage(), expectedPageB);
+}
+
 void PartTest::testForwardBackwardNavigation()
 {
     const QString testFile = QStringLiteral(KDESRCDIR "data/simple-multipage.pdf");
diff --git a/part.cpp b/part.cpp
index 76fa567e8..e648fc65e 100644
--- a/part.cpp
+++ b/part.cpp
@@ -1670,7 +1670,17 @@ bool Part::openUrl(const QUrl &_url, bool swapInsteadOfOpening)
     if (url.hasFragment()) {
         const QString dest = url.fragment(QUrl::FullyDecoded);
         bool ok = true;
-        const int page = dest.toInt(&ok);
+        int page = dest.toInt(&ok);
+
+        if (!ok) {
+            const QStringList parameters = dest.split(QChar('&'));
+            for (const QString &parameter : parameters) {
+                if (parameter.startsWith(QStringLiteral("page="), Qt::CaseInsensitive)) {
+                    page = dest.midRef(5).toInt(&ok);
+                }
+            }
+        }
+
         if (ok) {
             Okular::DocumentViewport vp(page - 1);
             vp.rePos.enabled = true;