2 files changed, 11 insertions, 2 deletions
diff --git a/src/tools/rcc/main.cpp b/src/tools/rcc/main.cpp
index 3873e74ee5..ad20b9e3ac 100644
--- a/src/tools/rcc/main.cpp
+++ b/src/tools/rcc/main.cpp
@@ -47,6 +47,8 @@
 #include <QFile>
 #include <QFileInfo>
 #include <QTextStream>
+#include <QAtomicInt>
+#include <QtGlobal>
 
 QT_BEGIN_NAMESPACE
 
@@ -254,9 +256,16 @@ int runRcc(int argc, char *argv[])
     return library.output(out, errorDevice) ? 0 : 1;
 }
 
+Q_CORE_EXPORT extern QBasicAtomicInt qt_qhash_seed; // from qhash.cpp
+
 QT_END_NAMESPACE
 
 int main(int argc, char *argv[])
 {
+    // rcc uses a QHash to store files in the resource system.
+    // we must force a certain hash order when testing or tst_rcc will fail, see QTBUG-25078
+    if (!qgetenv("QT_RCC_TEST").isEmpty() && !qt_qhash_seed.testAndSetRelaxed(-1, 0))
+        qFatal("Cannot force QHash seed for testing as requested");
+
     return QT_PREPEND_NAMESPACE(runRcc)(argc, argv);
 }
diff --git a/src/tools/rcc/rcc.cpp b/src/tools/rcc/rcc.cpp
index 740ae91b68..2f2cfb679b 100644
--- a/src/tools/rcc/rcc.cpp
+++ b/src/tools/rcc/rcc.cpp
@@ -298,7 +298,7 @@ qint64 RCCFileInfo::writeDataName(RCCResourceLibrary &lib, qint64 offset)
     offset += 2;
 
     // write the hash
-    lib.writeNumber4(qHash(m_name));
+    lib.writeNumber4(qt_hash(m_name));
     if (text)
         lib.writeString("\n  ");
     offset += 4;
@@ -882,7 +882,7 @@ bool RCCResourceLibrary::writeDataNames()
 
 static bool qt_rcc_compare_hash(const RCCFileInfo *left, const RCCFileInfo *right)
 {
-    return qHash(left->m_name) < qHash(right->m_name);
+    return qt_hash(left->m_name) < qt_hash(right->m_name);
 }
 
 bool RCCResourceLibrary::writeDataStructure()