diff -Nru baloo-kf5-5.57.0+p18.04+git20190412.1626/CMakeLists.txt baloo-kf5-5.57.0+p18.04+git20190416.1014/CMakeLists.txt
--- baloo-kf5-5.57.0+p18.04+git20190412.1626/CMakeLists.txt	2019-04-12 16:26:59.000000000 +0000
+++ baloo-kf5-5.57.0+p18.04+git20190416.1014/CMakeLists.txt	2019-04-16 10:14:54.000000000 +0000
@@ -1,7 +1,7 @@
 # set minimum version requirements
 cmake_minimum_required(VERSION 3.5)
 set(REQUIRED_QT_VERSION 5.10.0)
-set(KF5_VERSION "5.57.0") # handled by release scripts
+set(KF5_VERSION "5.58.0") # handled by release scripts
 set(KF5_DEP_VERSION "5.57.0") # handled by release scripts
 
 # set up project
diff -Nru baloo-kf5-5.57.0+p18.04+git20190412.1626/debian/changelog baloo-kf5-5.57.0+p18.04+git20190416.1014/debian/changelog
--- baloo-kf5-5.57.0+p18.04+git20190412.1626/debian/changelog	2019-04-12 16:27:00.000000000 +0000
+++ baloo-kf5-5.57.0+p18.04+git20190416.1014/debian/changelog	2019-04-16 10:14:55.000000000 +0000
@@ -1,4 +1,4 @@
-baloo-kf5 (5.57.0+p18.04+git20190412.1626-0) bionic; urgency=high
+baloo-kf5 (5.57.0+p18.04+git20190416.1014-0) bionic; urgency=high
 
   [ Rik Mills ]
   * New upstream release (5.57.0)
@@ -6,7 +6,7 @@
   [ Kubuntu CI ]
   * Automatic Ubuntu CI Build
 
- -- Kubuntu CI <kubuntu-ci@lists.launchpad.net>  Fri, 12 Apr 2019 16:27:00 +0000
+ -- Kubuntu CI <kubuntu-ci@lists.launchpad.net>  Tue, 16 Apr 2019 10:14:55 +0000
 
 baloo-kf5 (5.56.0-0ubuntu1) disco; urgency=medium
 
diff -Nru baloo-kf5-5.57.0+p18.04+git20190412.1626/src/file/extractor/result.cpp baloo-kf5-5.57.0+p18.04+git20190416.1014/src/file/extractor/result.cpp
--- baloo-kf5-5.57.0+p18.04+git20190412.1626/src/file/extractor/result.cpp	2019-04-12 16:26:59.000000000 +0000
+++ baloo-kf5-5.57.0+p18.04+git20190416.1014/src/file/extractor/result.cpp	2019-04-16 10:14:54.000000000 +0000
@@ -121,6 +121,10 @@
 
 void Result::finish()
 {
+    if (m_map.isEmpty()) {
+        m_doc.setData(QByteArray());
+        return;
+    }
     QJsonObject jo = QJsonObject::fromVariantMap(m_map);
     QJsonDocument jdoc;
     jdoc.setObject(jo);
diff -Nru baloo-kf5-5.57.0+p18.04+git20190412.1626/src/lib/file.cpp baloo-kf5-5.57.0+p18.04+git20190416.1014/src/lib/file.cpp
--- baloo-kf5-5.57.0+p18.04+git20190412.1626/src/lib/file.cpp	2019-04-12 16:26:59.000000000 +0000
+++ baloo-kf5-5.57.0+p18.04+git20190416.1014/src/lib/file.cpp	2019-04-16 10:14:54.000000000 +0000
@@ -112,7 +112,8 @@
         Transaction tr(db, Transaction::ReadOnly);
         arr = tr.documentData(id);
     }
-    if (arr.isEmpty()) {
+    // Ignore empty JSON documents, i.e. "" or "{}"
+    if (arr.isEmpty() || arr.size() <= 2) {
         return false;
     }
 
diff -Nru baloo-kf5-5.57.0+p18.04+git20190412.1626/src/tools/balooshow/main.cpp baloo-kf5-5.57.0+p18.04+git20190416.1014/src/tools/balooshow/main.cpp
--- baloo-kf5-5.57.0+p18.04+git20190412.1626/src/tools/balooshow/main.cpp	2019-04-12 16:26:59.000000000 +0000
+++ baloo-kf5-5.57.0+p18.04+git20190416.1014/src/tools/balooshow/main.cpp	2019-04-16 10:14:54.000000000 +0000
@@ -122,7 +122,7 @@
                 fid = tr.documentId(QFile::encodeName(url));
                 internalUrl = QFile::decodeName(tr.documentUrl(fsFid));
 
-                if (fid != fsFid) {
+                if (fid && fid != fsFid) {
                     stream << i18n("The document IDs of the Baloo DB and the filesystem are different:") <<  "\n";
                     auto dbInode = Baloo::idToInode(fid);
                     auto fsInode = Baloo::idToInode(fsFid);
@@ -134,6 +134,7 @@
                     stream << "Inode:    " << dbInode << " (DB) " << (dbInode == fsInode ? "== " : "<-> ") << fsInode << " (FS)\n";
                     stream << "DeviceID: " << dbDevId << " (DB) " << (dbDevId == fsDevId ? "== " : "<-> ") << fsDevId << " (FS)" << endl;
                 }
+                fid = fsFid;
             } else {
                 bool ok;
                 fid = url.toULongLong(&ok);