Merge remote-tracking branch 'origin/5.4.1' into 5.4

Change-Id: Idadb5639da6e55e7ac8cc30eedf76d147d8d5d23

9 files changed, 153 insertions, 60 deletions

diff --git a/src/gui/kernel/qdnd.cpp b/src/gui/kernel/qdnd.cpp
index f515fe18df..2a6cc4fc99 100644
--- a/src/gui/kernel/qdnd.cpp
+++ b/src/gui/kernel/qdnd.cpp
@@ -134,7 +134,8 @@ Qt::DropAction QDragManager::drag(QDrag *o)
     QGuiApplicationPrivate::instance()->notifyDragStarted(o);
     const Qt::DropAction result = m_platformDrag->drag(m_object);
     m_object = 0;
-    o->deleteLater();
+    if (!m_platformDrag->ownsDragObject())
+        o->deleteLater();
     return result;
 }
 
diff --git a/src/gui/kernel/qplatformdrag.cpp b/src/gui/kernel/qplatformdrag.cpp
index 8a5c7264d1..326f092ead 100644
--- a/src/gui/kernel/qplatformdrag.cpp
+++ b/src/gui/kernel/qplatformdrag.cpp
@@ -241,6 +241,18 @@ QPixmap QPlatformDrag::defaultPixmap()
     return *qt_drag_default_pixmap();
 }
 
+/*!
+    \since 5.4
+    \brief Returns bool indicating whether QPlatformDrag takes ownership
+    and therefore responsibility of deleting the QDrag object passed in
+    from QPlatformDrag::drag. This can be useful on platforms where QDrag
+    object has to be kept around.
+ */
+bool QPlatformDrag::ownsDragObject() const
+{
+    return false;
+}
+
 #endif // QT_NO_DRAGANDDROP
 
 QT_END_NAMESPACE
diff --git a/src/gui/kernel/qplatformdrag.h b/src/gui/kernel/qplatformdrag.h
index 34ad11e45f..ce7a9aa1f2 100644
--- a/src/gui/kernel/qplatformdrag.h
+++ b/src/gui/kernel/qplatformdrag.h
@@ -98,6 +98,8 @@ public:
 
     static QPixmap defaultPixmap();
 
+    virtual bool ownsDragObject() const;
+
 private:
     QPlatformDragPrivate *d_ptr;
 
diff --git a/src/gui/opengl/qopenglextensions_p.h b/src/gui/opengl/qopenglextensions_p.h
index 23cfe16467..f53addaf0e 100644
--- a/src/gui/opengl/qopenglextensions_p.h
+++ b/src/gui/opengl/qopenglextensions_p.h
@@ -46,11 +46,36 @@
 //
 
 #include "qopenglfunctions.h"
+#include <QtCore/qlibrary.h>
 
 QT_BEGIN_NAMESPACE
 
 class QOpenGLExtensionsPrivate;
 
+class QOpenGLES3Helper
+{
+public:
+    QOpenGLES3Helper();
+
+    GLvoid* (QOPENGLF_APIENTRYP MapBufferRange)(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr length, GLbitfield access);
+    GLboolean (QOPENGLF_APIENTRYP UnmapBuffer)(GLenum target);
+    void (QOPENGLF_APIENTRYP BlitFramebuffer)(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1, GLbitfield mask, GLenum filter);
+    void (QOPENGLF_APIENTRYP RenderbufferStorageMultisample)(GLenum target, GLsizei samples, GLenum internalFormat, GLsizei width, GLsizei height);
+
+    void (QOPENGLF_APIENTRYP GenVertexArrays)(GLsizei n, GLuint *arrays);
+    void (QOPENGLF_APIENTRYP DeleteVertexArrays)(GLsizei n, const GLuint *arrays);
+    void (QOPENGLF_APIENTRYP BindVertexArray)(GLuint array);
+    GLboolean (QOPENGLF_APIENTRYP IsVertexArray)(GLuint array);
+
+    void (QOPENGLF_APIENTRYP TexImage3D)(GLenum target, GLint level, GLint internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLenum format, GLenum type, const GLvoid *pixels);
+    void (QOPENGLF_APIENTRYP TexSubImage3D)(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const GLvoid *pixels);
+    void (QOPENGLF_APIENTRYP CompressedTexImage3D)(GLenum target, GLint level, GLenum internalFormat, GLsizei width, GLsizei height, GLsizei depth, GLint border, GLsizei imageSize, const GLvoid *data);
+    void (QOPENGLF_APIENTRYP CompressedTexSubImage3D)(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLsizei imageSize, const GLvoid *data);
+
+private:
+    QLibrary m_gl;
+};
+
 class Q_GUI_EXPORT QOpenGLExtensions : public QOpenGLFunctions
 {
     Q_DECLARE_PRIVATE(QOpenGLExtensions)
@@ -102,6 +127,8 @@ public:
 
     void glGetBufferSubData(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr size, GLvoid *data);
 
+    QOpenGLES3Helper *gles3Helper();
+
 private:
     static bool isInitialized(const QOpenGLFunctionsPrivate *d) { return d != 0; }
 };
diff --git a/src/gui/opengl/qopenglfunctions.cpp b/src/gui/opengl/qopenglfunctions.cpp
index 44b56699df..d561e65d8e 100644
--- a/src/gui/opengl/qopenglfunctions.cpp
+++ b/src/gui/opengl/qopenglfunctions.cpp
@@ -3187,65 +3187,105 @@ static void QOPENGLF_APIENTRY qopenglfResolveVertexAttribPointer(GLuint indx, GL
 
 #endif // !QT_OPENGL_ES_2
 
+// Functions part of the OpenGL ES 3.0+ standard need special handling. These,
+// just like the 2.0 functions, are not guaranteed to be resolvable via
+// eglGetProcAddress or similar. Calling them directly is, unlike the 2.0
+// functions, not feasible because one may build the binaries on a GLES3-capable
+// system and then deploy on a GLES2-only system that does not have these
+// symbols. Until ES3 gets universally available, they have to be dlsym'ed.
+
+Q_GLOBAL_STATIC(QOpenGLES3Helper, qgles3Helper)
+
+QOpenGLES3Helper::QOpenGLES3Helper()
+{
+#ifdef Q_OS_WIN
+#ifdef QT_DEBUG
+    m_gl.setFileName(QStringLiteral("libGLESv2"));
+#else
+    m_gl.setFileName(QStringLiteral("libGLESv2d"));
+#endif
+#else
+    m_gl.setFileName(QStringLiteral("GLESv2"));
+#endif
+    if (m_gl.load()) {
+        MapBufferRange = (GLvoid* (QOPENGLF_APIENTRYP)(GLenum, qopengl_GLintptr, qopengl_GLsizeiptr, GLbitfield)) m_gl.resolve("glMapBufferRange");
+        UnmapBuffer = (GLboolean (QOPENGLF_APIENTRYP)(GLenum)) m_gl.resolve("glUnmapBuffer");
+        BlitFramebuffer = (void (QOPENGLF_APIENTRYP)(GLint, GLint, GLint, GLint, GLint, GLint, GLint, GLint, GLbitfield, GLenum)) m_gl.resolve("glBlitFramebuffer");
+        RenderbufferStorageMultisample = (void (QOPENGLF_APIENTRYP)(GLenum, GLsizei, GLenum, GLsizei, GLsizei)) m_gl.resolve("glRenderbufferStorageMultisample");
+
+        GenVertexArrays = (void (QOPENGLF_APIENTRYP)(GLsizei, GLuint *)) m_gl.resolve("glGenVertexArrays");
+        DeleteVertexArrays = (void (QOPENGLF_APIENTRYP)(GLsizei, const GLuint *)) m_gl.resolve("glDeleteVertexArrays");
+        BindVertexArray = (void (QOPENGLF_APIENTRYP)(GLuint)) m_gl.resolve("glBindVertexArray");
+        IsVertexArray = (GLboolean (QOPENGLF_APIENTRYP)(GLuint)) m_gl.resolve("glIsVertexArray");
+
+        TexImage3D = (void (QOPENGLF_APIENTRYP)(GLenum, GLint, GLint, GLsizei, GLsizei, GLsizei, GLint, GLenum, GLenum, const GLvoid *)) m_gl.resolve("glTexImage3D");
+        TexSubImage3D = (void (QOPENGLF_APIENTRYP)(GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei, GLenum, GLenum, const GLvoid *)) m_gl.resolve("glTexSubImage3D");
+        CompressedTexImage3D = (void (QOPENGLF_APIENTRYP)(GLenum, GLint, GLenum, GLsizei, GLsizei, GLsizei, GLint, GLsizei, const GLvoid *)) m_gl.resolve("glCompressedTexImage3D");
+        CompressedTexSubImage3D = (void (QOPENGLF_APIENTRYP)(GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei, GLenum, GLsizei, const GLvoid *)) m_gl.resolve("glCompressedTexSubImage3D");
+
+        if (!MapBufferRange || !GenVertexArrays || !TexImage3D)
+            qFatal("OpenGL ES 3.0 entry points not found");
+    } else {
+        qFatal("Failed to load libGLESv2");
+    }
+}
+
+static inline bool isES3()
+{
+    QOpenGLContext *ctx = QOpenGLContext::currentContext();
+    return ctx->isOpenGLES() && ctx->format().majorVersion() >= 3;
+}
+
 static GLvoid *QOPENGLF_APIENTRY qopenglfResolveMapBuffer(GLenum target, GLenum access)
 {
-#ifdef QT_OPENGL_ES_3
     // It is possible that GL_OES_map_buffer is present, but then having to
     // differentiate between glUnmapBufferOES and glUnmapBuffer causes extra
     // headache. QOpenGLBuffer::map() will handle this automatically, while direct
     // calls are better off with migrating to the standard glMapBufferRange.
-    if (QOpenGLContext::currentContext()->format().majorVersion() >= 3) {
+    if (isES3()) {
         qWarning("QOpenGLFunctions: glMapBuffer is not available in OpenGL ES 3.0 and up. Use glMapBufferRange instead.");
         return 0;
-    } else
-#endif
-    RESOLVE_FUNC(GLvoid *, ResolveOES, MapBuffer)(target, access);
+    } else {
+        RESOLVE_FUNC(GLvoid *, ResolveOES, MapBuffer)(target, access);
+    }
 }
 
 static GLvoid *QOPENGLF_APIENTRY qopenglfResolveMapBufferRange(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr length, GLbitfield access)
 {
-#ifdef QT_OPENGL_ES_3
-    if (QOpenGLContext::currentContext()->format().majorVersion() >= 3)
-        return ::glMapBufferRange(target, offset, length, access);
+    if (isES3())
+        return qgles3Helper()->MapBufferRange(target, offset, length, access);
     else
-#endif
-    RESOLVE_FUNC(GLvoid *, 0, MapBufferRange)(target, offset, length, access);
+        RESOLVE_FUNC(GLvoid *, 0, MapBufferRange)(target, offset, length, access);
 }
 
 static GLboolean QOPENGLF_APIENTRY qopenglfResolveUnmapBuffer(GLenum target)
 {
-#ifdef QT_OPENGL_ES_3
-    if (QOpenGLContext::currentContext()->format().majorVersion() >= 3)
-        return ::glUnmapBuffer(target);
+    if (isES3())
+        return qgles3Helper()->UnmapBuffer(target);
     else
-#endif
-    RESOLVE_FUNC(GLboolean, ResolveOES, UnmapBuffer)(target);
+        RESOLVE_FUNC(GLboolean, ResolveOES, UnmapBuffer)(target);
 }
 
 static void QOPENGLF_APIENTRY qopenglfResolveBlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
                        GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
                        GLbitfield mask, GLenum filter)
 {
-#ifdef QT_OPENGL_ES_3
-    if (QOpenGLContext::currentContext()->format().majorVersion() >= 3)
-        ::glBlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
+    if (isES3())
+        qgles3Helper()->BlitFramebuffer(srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
     else
-#endif
-    RESOLVE_FUNC_VOID(ResolveEXT | ResolveANGLE | ResolveNV, BlitFramebuffer)
-        (srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
+        RESOLVE_FUNC_VOID(ResolveEXT | ResolveANGLE | ResolveNV, BlitFramebuffer)
+            (srcX0, srcY0, srcX1, srcY1, dstX0, dstY0, dstX1, dstY1, mask, filter);
 }
 
 static void QOPENGLF_APIENTRY qopenglfResolveRenderbufferStorageMultisample(GLenum target, GLsizei samples,
                                       GLenum internalFormat,
                                       GLsizei width, GLsizei height)
 {
-#ifdef QT_OPENGL_ES_3
-    if (QOpenGLContext::currentContext()->format().majorVersion() >= 3)
-        ::glRenderbufferStorageMultisample(target, samples, internalFormat, width, height);
+    if (isES3())
+        qgles3Helper()->RenderbufferStorageMultisample(target, samples, internalFormat, width, height);
     else
-#endif
-    RESOLVE_FUNC_VOID(ResolveEXT | ResolveANGLE | ResolveNV, RenderbufferStorageMultisample)
-        (target, samples, internalFormat, width, height);
+        RESOLVE_FUNC_VOID(ResolveEXT | ResolveANGLE | ResolveNV, RenderbufferStorageMultisample)
+            (target, samples, internalFormat, width, height);
 }
 
 static void QOPENGLF_APIENTRY qopenglfResolveGetBufferSubData(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr size, GLvoid *data)
@@ -3494,4 +3534,9 @@ QOpenGLExtensionsPrivate::QOpenGLExtensionsPrivate(QOpenGLContext *ctx)
     GetBufferSubData = qopenglfResolveGetBufferSubData;
 }
 
+QOpenGLES3Helper *QOpenGLExtensions::gles3Helper()
+{
+    return qgles3Helper();
+}
+
 QT_END_NAMESPACE
diff --git a/src/gui/opengl/qopengltexturehelper.cpp b/src/gui/opengl/qopengltexturehelper.cpp
index 29cecf0ea8..e1e3593f4f 100644
--- a/src/gui/opengl/qopengltexturehelper.cpp
+++ b/src/gui/opengl/qopengltexturehelper.cpp
@@ -34,6 +34,7 @@
 #include "qopengltexturehelper_p.h"
 
 #include <QOpenGLContext>
+#include <private/qopenglextensions_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -242,21 +243,23 @@ QOpenGLTextureHelper::QOpenGLTextureHelper(QOpenGLContext *context)
         CompressedTexImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum, GLint, GLenum, GLsizei, GLsizei, GLsizei, GLint, GLsizei, const GLvoid*)>(context->getProcAddress(QByteArrayLiteral("glCompressedTexImage3DOES")));
         CompressedTexSubImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum, GLint, GLint, GLint, GLint, GLsizei, GLsizei, GLsizei, GLenum, GLsizei, const GLvoid*)>(context->getProcAddress(QByteArrayLiteral("glCompressedTexSubImage3DOES")));
     } else {
-#ifdef QT_OPENGL_ES_3
-        // OpenGL ES 3.0+ has glTexImage3D.
-        TexImage3D = ::glTexImage3D;
-        TexSubImage3D = ::glTexSubImage3D;
-        CompressedTexImage3D = ::glCompressedTexImage3D;
-        CompressedTexSubImage3D = ::glCompressedTexSubImage3D;
-#else
-        // OpenGL 1.2
-        TexImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLint , GLsizei , GLsizei , GLsizei , GLint , GLenum , GLenum , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glTexImage3D")));
-        TexSubImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLint , GLint , GLint , GLsizei , GLsizei , GLsizei , GLenum , GLenum , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glTexSubImage3D")));
-
-        // OpenGL 1.3
-        CompressedTexImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLenum , GLsizei , GLsizei , GLsizei , GLint , GLsizei , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glCompressedTexImage3D")));
-        CompressedTexSubImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLint , GLint , GLint , GLsizei , GLsizei , GLsizei , GLenum , GLsizei , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glCompressedTexSubImage3D")));
-#endif
+        QOpenGLContext *ctx = QOpenGLContext::currentContext();
+        if (ctx->isOpenGLES() && ctx->format().majorVersion() >= 3) {
+            // OpenGL ES 3.0+ has glTexImage3D.
+            QOpenGLES3Helper *es3 = static_cast<QOpenGLExtensions *>(ctx->functions())->gles3Helper();
+            TexImage3D = es3->TexImage3D;
+            TexSubImage3D = es3->TexSubImage3D;
+            CompressedTexImage3D = es3->CompressedTexImage3D;
+            CompressedTexSubImage3D = es3->CompressedTexSubImage3D;
+        } else {
+            // OpenGL 1.2
+            TexImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLint , GLsizei , GLsizei , GLsizei , GLint , GLenum , GLenum , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glTexImage3D")));
+            TexSubImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLint , GLint , GLint , GLsizei , GLsizei , GLsizei , GLenum , GLenum , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glTexSubImage3D")));
+
+            // OpenGL 1.3
+            CompressedTexImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLenum , GLsizei , GLsizei , GLsizei , GLint , GLsizei , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glCompressedTexImage3D")));
+            CompressedTexSubImage3D = reinterpret_cast<void (QOPENGLF_APIENTRYP)(GLenum , GLint , GLint , GLint , GLint , GLsizei , GLsizei , GLsizei , GLenum , GLsizei , const GLvoid *)>(context->getProcAddress(QByteArrayLiteral("glCompressedTexSubImage3D")));
+        }
     }
 
 #ifndef QT_OPENGL_ES_2
diff --git a/src/gui/opengl/qopenglvertexarrayobject.cpp b/src/gui/opengl/qopenglvertexarrayobject.cpp
index 5520dfed08..d3eadf9ae1 100644
--- a/src/gui/opengl/qopenglvertexarrayobject.cpp
+++ b/src/gui/opengl/qopenglvertexarrayobject.cpp
@@ -35,12 +35,12 @@
 
 #include <QtCore/private/qobject_p.h>
 #include <QtGui/qopenglcontext.h>
-#include <QtGui/qopenglfunctions.h>
 #include <QtGui/qoffscreensurface.h>
 
 #include <QtGui/qopenglfunctions_3_0.h>
 #include <QtGui/qopenglfunctions_3_2_core.h>
 
+#include <private/qopenglextensions_p.h>
 #include <private/qopenglvertexarrayobject_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -56,16 +56,14 @@ void qtInitializeVertexArrayObjectHelper(QOpenGLVertexArrayObjectHelper *helper,
     bool tryARB = true;
 
     if (context->isOpenGLES()) {
-#ifdef QT_OPENGL_ES_3
         if (context->format().majorVersion() >= 3) {
-            helper->GenVertexArrays = ::glGenVertexArrays;
-            helper->DeleteVertexArrays = ::glDeleteVertexArrays;
-            helper->BindVertexArray = ::glBindVertexArray;
-            helper->IsVertexArray = ::glIsVertexArray;
+            QOpenGLES3Helper *es3 = static_cast<QOpenGLExtensions *>(context->functions())->gles3Helper();
+            helper->GenVertexArrays = es3->GenVertexArrays;
+            helper->DeleteVertexArrays = es3->DeleteVertexArrays;
+            helper->BindVertexArray = es3->BindVertexArray;
+            helper->IsVertexArray = es3->IsVertexArray;
             tryARB = false;
-        } else
-#endif
-        if (context->hasExtension(QByteArrayLiteral("GL_OES_vertex_array_object"))) {
+        } else if (context->hasExtension(QByteArrayLiteral("GL_OES_vertex_array_object"))) {
             helper->GenVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_GenVertexArrays_t>(context->getProcAddress(QByteArrayLiteral("glGenVertexArraysOES")));
             helper->DeleteVertexArrays = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_DeleteVertexArrays_t>(context->getProcAddress(QByteArrayLiteral("glDeleteVertexArraysOES")));
             helper->BindVertexArray = reinterpret_cast<QOpenGLVertexArrayObjectHelper::qt_BindVertexArray_t>(context->getProcAddress(QByteArrayLiteral("glBindVertexArrayOES")));
diff --git a/src/gui/text/qfontengine.cpp b/src/gui/text/qfontengine.cpp
index b2a7a8e91f..b360ed5c85 100644
--- a/src/gui/text/qfontengine.cpp
+++ b/src/gui/text/qfontengine.cpp
@@ -77,7 +77,12 @@ static inline bool qtransform_equals_no_translate(const QTransform &a, const QTr
 // Harfbuzz helper functions
 
 #ifdef QT_ENABLE_HARFBUZZ_NG
-bool useHarfbuzzNG = qgetenv("QT_HARFBUZZ") != "old";
+Q_GLOBAL_STATIC_WITH_ARGS(bool, useHarfbuzzNG,(qgetenv("QT_HARFBUZZ") != "old"))
+
+bool qt_useHarfbuzzNG()
+{
+    return *useHarfbuzzNG();
+}
 #endif
 
 Q_STATIC_ASSERT(sizeof(HB_Glyph) == sizeof(glyph_t));
@@ -282,7 +287,7 @@ void *QFontEngine::harfbuzzFont() const
 {
     Q_ASSERT(type() != QFontEngine::Multi);
 #ifdef QT_ENABLE_HARFBUZZ_NG
-    if (useHarfbuzzNG)
+    if (qt_useHarfbuzzNG())
         return hb_qt_font_get_for_engine(const_cast<QFontEngine *>(this));
 #endif
     if (!font_) {
@@ -318,7 +323,7 @@ void *QFontEngine::harfbuzzFace() const
 {
     Q_ASSERT(type() != QFontEngine::Multi);
 #ifdef QT_ENABLE_HARFBUZZ_NG
-    if (useHarfbuzzNG)
+    if (qt_useHarfbuzzNG())
         return hb_qt_face_get_for_engine(const_cast<QFontEngine *>(this));
 #endif
     if (!face_) {
@@ -360,7 +365,7 @@ bool QFontEngine::supportsScript(QChar::Script script) const
 #endif
 
 #ifdef QT_ENABLE_HARFBUZZ_NG
-    if (useHarfbuzzNG) {
+    if (qt_useHarfbuzzNG()) {
         bool ret = false;
         if (hb_face_t *face = hb_qt_face_get_for_engine(const_cast<QFontEngine *>(this))) {
             hb_tag_t script_tag_1, script_tag_2;
diff --git a/src/gui/text/qtextengine.cpp b/src/gui/text/qtextengine.cpp
index 8f60847250..8f874e0245 100644
--- a/src/gui/text/qtextengine.cpp
+++ b/src/gui/text/qtextengine.cpp
@@ -938,7 +938,7 @@ void QTextEngine::shapeLine(const QScriptLine &line)
 }
 
 #ifdef QT_ENABLE_HARFBUZZ_NG
-extern bool useHarfbuzzNG; // defined in qfontengine.cpp
+extern bool qt_useHarfbuzzNG(); // defined in qfontengine.cpp
 #endif
 
 void QTextEngine::shapeText(int item) const
@@ -1051,7 +1051,7 @@ void QTextEngine::shapeText(int item) const
     }
 
 #ifdef QT_ENABLE_HARFBUZZ_NG
-    if (useHarfbuzzNG)
+    if (qt_useHarfbuzzNG())
         si.num_glyphs = shapeTextWithHarfbuzzNG(si, string, itemLength, fontEngine, itemBoundaries, kerningEnabled);
     else
 #endif
@@ -1067,7 +1067,7 @@ void QTextEngine::shapeText(int item) const
     QGlyphLayout glyphs = shapedGlyphs(&si);
 
 #ifdef QT_ENABLE_HARFBUZZ_NG
-    if (useHarfbuzzNG)
+    if (qt_useHarfbuzzNG())
         qt_getJustificationOpportunities(string, itemLength, si, glyphs, logClusters(&si));
 #endif
 
@@ -1616,7 +1616,7 @@ void QTextEngine::itemize() const
     }
 #ifdef QT_ENABLE_HARFBUZZ_NG
     analysis = scriptAnalysis.data();
-    if (useHarfbuzzNG) {
+    if (qt_useHarfbuzzNG()) {
         // ### pretend HB-old behavior for now
         for (int i = 0; i < length; ++i) {
             switch (analysis[i].script) {