Index: src/document/katedocument.h
===================================================================
--- src/document/katedocument.h
+++ src/document/katedocument.h
@@ -939,6 +939,7 @@
 
 private:
     void updateDocName();
+    void setDocumentName(const QString &name, int number = -1);
 
 public:
     /**
@@ -1363,10 +1364,6 @@
      */
     bool m_readWriteStateBeforeLoading = false;
 
-    /**
-     * if the document is untitled
-     */
-    bool m_isUntitled = true;
     /**
      * loading job, we want to cancel with cancel in the loading message
      */
Index: src/document/katedocument.cpp
===================================================================
--- src/document/katedocument.cpp
+++ src/document/katedocument.cpp
@@ -198,18 +198,11 @@
     : KTextEditor::Document (this, parent),
       m_bSingleViewMode(bSingleViewMode),
       m_bReadOnly(bReadOnly),
-
       m_undoManager(new KateUndoManager(this)),
-
       m_buffer(new KateBuffer(this)),
       m_indenter(new KateAutoIndent(this)),
-
-      m_docName(QStringLiteral("need init")),
-
       m_fileType(QStringLiteral("Normal")),
-
       m_config(new KateDocumentConfig(this))
-
 {
     /**
      * no plugins from kparts here
@@ -4231,44 +4224,130 @@
            .replace(QLatin1Char('\n'), QLatin1Char(' '));
 }
 
+static QStringList reverseSplittedUrl(const QUrl &url) {
+
+    QString fullUrl = removeNewLines(url.url());
+
+    if (fullUrl.isEmpty()) {
+        return QStringList();
+    }
+
+    QStringList splittedUrl = fullUrl.split(QLatin1Char('/'), QString::SkipEmptyParts);
+
+    // Remove not useful parts...
+    splittedUrl.removeLast(); // The file name
+    // ...to avoid odd naming in rare cases we force numbering fallback
+    if (splittedUrl.at(0) == QLatin1String("file:")) {
+        splittedUrl.removeAt(0);
+        if (splittedUrl.at(0) == QLatin1String("home")) {
+            splittedUrl.removeAt(0);
+        }
+    }
+
+    // Reverse our url; Thanks to https://stackoverflow.com/a/20652805
+    for(int k = 0, s = splittedUrl.size(), max = (s / 2); k < max; k++) {
+        splittedUrl.swap(k, s - (1 + k));
+    }
+
+    return splittedUrl;
+}
+
 void KTextEditor::DocumentPrivate::updateDocName()
 {
+    QString fileName = removeNewLines(url().fileName());
+
     // if the name is set, and starts with FILENAME, it should not be changed!
-    if (! url().isEmpty()
-            && (m_docName == removeNewLines(url().fileName()) ||
-                m_docName.startsWith(removeNewLines(url().fileName()) + QLatin1String(" (")))) {
+    if (! url().isEmpty() && m_docName.startsWith(fileName)) {
         return;
     }
 
-    int count = -1;
+    QString newName = m_docName;
+
+    if (m_docName.isEmpty() && url().isEmpty()) {
+        newName = i18n("Untitled");
+    } else if (m_docName == i18n("Untitled") && !url().isEmpty()) {
+        newName = fileName;
+    }
+
+    // Collect all files with same name...
+    typedef QPair<KTextEditor::DocumentPrivate*, QStringList> FooPair;
+    QList<FooPair> fooList;
+    // ...and save to each the url in a special rehashed form, starting with current document
+    fooList << FooPair(this, reverseSplittedUrl(url()));
 
+    int count = -1; // To catch multiple "Untitled" case only
     foreach (KTextEditor::DocumentPrivate *doc, KTextEditor::EditorPrivate::self()->kateDocuments()) {
-        if ((doc != this) && (doc->url().fileName() == url().fileName()))
-            if (doc->m_docNameNumber > count) {
-                count = doc->m_docNameNumber;
-            }
+        if ((doc != this) && (doc->url().fileName() == url().fileName())) {
+            count = qMax(count, doc->m_docNameNumber);
+            fooList << FooPair(doc, reverseSplittedUrl(doc->url()));
+        }
     }
 
-    m_docNameNumber = count + 1;
+    // Did we find at least two files with same name?
+    if (fooList.size() > 1 && !url().isEmpty()) {
+        count = -1; // Count not unique names as fallback
+        // Sort our list with shortest url on top (position 0)
+        std::sort(fooList.begin(), fooList.end(), [](FooPair a, FooPair b) { return a.second.size() < b.second.size(); });
+        QSet<QString> uniqueNames; // Remember given names
+        // To make an unique name, prefix some folder name to the document name
+        for (QList<FooPair>::iterator i = fooList.begin(); i != fooList.end(); ++i) {
+            if (!(*i).second.size()) {
+                // Can happen in rare cases due to quirks in reverseSplittedUrl(..); use numbering scheme fallback
+                (*i).first->setDocumentName(fileName, count++);
+                continue;
+            }
+
+            // First Try: Is the folder name, where file is located, enough to be unique?
+            QString docName = (*i).second.at(0) + QLatin1String("/") + fileName;
+            if (!uniqueNames.contains(docName)) {
+                uniqueNames.insert(docName);
+                (*i).first->setDocumentName(docName);
 
-    QString oldName = m_docName;
-    m_docName = removeNewLines(url().fileName());
+            } else {
+                // Second Try: Find a folder name somewhere above to become an unique name
+                bool noSuccess = true;
+                for (int j = 1; j < (*i).second.size(); ++j) {
+                 // docName = (*i).second.at(j) + QLatin1String("/…/") + fileName; // Bad shown, why?
+                 // docName = (*i).second.at(j) + QLatin1String("/~/") + fileName; // How about that?
+                    docName = (*i).second.at(j) + QLatin1String("/.../") + fileName;
+                    if (!uniqueNames.contains(docName)) {
+                        uniqueNames.insert(docName);
+                        (*i).first->setDocumentName(docName);
+                        noSuccess = false;
+                        break;
+                    }
+                }
+                // Third: We need to use the numbering scheme fallback
+                if (noSuccess) {
+                    (*i).first->setDocumentName(fileName, count++);
+                }
+            }
+        }
 
-    m_isUntitled = m_docName.isEmpty();
-    if (m_isUntitled) {
-        m_docName = i18n("Untitled");
+    // Either no doubles or an "Untitled" document
+    } else {
+        setDocumentName(newName, count);
     }
+}
+
+void KTextEditor::DocumentPrivate::setDocumentName(const QString &name, int number /*= -1*/)
+{
+    m_docNameNumber = number + 1;
+
+    QString newName = name;
 
     if (m_docNameNumber > 0) {
-        m_docName = QString(m_docName + QLatin1String(" (%1)")).arg(m_docNameNumber + 1);
+        // Should rarely happens in normal cases, but always when we have more than one "Untitled" document
+        newName = QString(name + QLatin1String(" (%1)")).arg(m_docNameNumber + 1);
     }
 
-    /**
-     * avoid to emit this, if name doesn't change!
-     */
-    if (oldName != m_docName) {
-        emit documentNameChanged(this);
+    if (newName == m_docName) {
+        return;
     }
+
+    m_docName = newName;
+
+    emit documentNameChanged(this);
 }
 
 void KTextEditor::DocumentPrivate::slotModifiedOnDisk(KTextEditor::View * /*v*/)