Don't try to manually build url if parent is not set.

src/Logging.cpp

@@ -20,3 +20,4 @@
 #include "Logging.h"
 
 Q_LOGGING_CATEGORY(kdeMain, "org.kde.kdiff3")
+Q_LOGGING_CATEGORY(kdiffFileAccess, "org.kde.kdiff3.fileAccess")

src/Logging.h

@@ -22,4 +22,5 @@
 #include <QLoggingCategory>
 
 Q_DECLARE_LOGGING_CATEGORY(kdeMain)
+Q_DECLARE_LOGGING_CATEGORY(kdiffFileAccess)
 #endif // !LOGGING_H

src/fileaccess.cpp

@@ -10,6 +10,7 @@
 #include "fileaccess.h"
 #include "cvsignorelist.h"
 #include "common.h"
+#include "Logging.h"
 #include "progress.h"
 #include "Utils.h"
 
@@ -282,9 +283,22 @@ void FileAccess::setFromUdsEntry(const KIO::UDSEntry& e, FileAccess *parent)
     m_fileInfo.setCaching(true);
     if(m_url.isEmpty())
     {
-        m_url = parent->url().resolved(QUrl(filePath));
-        //Verify that the scheme doesn't change.
-        Q_ASSERT(m_url.scheme() == parent->url().scheme());
+        if(parent != nullptr)
+        {
+            m_url = parent->url().resolved(QUrl(filePath));
+            //Verify that the scheme doesn't change.
+            Q_ASSERT(m_url.scheme() == parent->url().scheme());
+        }
+        else
+        {
+            /*
+             Invalid entry we don't know the full url because KIO didn't tell us and there is no parent
+             node supplied.
+             This is a bug if it happens and should be logged . However it is a recoverable error.
+            */
+            qCWarning(kdiffFileAccess) << i18n("Unable to determine full url. No parent specified.");
+            return;
+        }
     }
 
     m_name = m_fileInfo.fileName();

src/pdiff.cpp

@@ -157,6 +157,7 @@ void KDiff3App::mainInit(TotalDiffStatus* pTotalDiffStatus, bool bLoadFiles, boo
         // First get all input data.
         pp.setInformation(i18n("Loading A"));
 
+        qCInfo(kdeMain) << i18n("Loading A: %1", m_sd1.getFilename());
         if(bUseCurrentEncoding)
             errors = m_sd1.readAndPreprocess(m_sd1.getEncoding(), false);
         else