From edfac1a9edb9c9c76ca9a97a0f9d7a5bfd83143b Mon Sep 17 00:00:00 2001
From: Alex Trotsenko <alex1973tr@gmail.com>
Date: Mon, 21 Jul 2014 16:35:43 +0300
Subject: [PATCH] Make QRingBuffer::append() not leave empty arrays in buffer
 list

Change-Id: I4c5af33488a70996299289ec2b953b7bf3b2c428
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
---
 src/corelib/tools/qringbuffer_p.h                 | 10 +++++++---
 .../corelib/tools/qringbuffer/tst_qringbuffer.cpp | 15 +++++++++++++++
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/src/corelib/tools/qringbuffer_p.h b/src/corelib/tools/qringbuffer_p.h
index 2f208d21e3..afd15c85ea 100644
--- a/src/corelib/tools/qringbuffer_p.h
+++ b/src/corelib/tools/qringbuffer_p.h
@@ -369,9 +369,13 @@ public:
 
     // append a new buffer to the end
     inline void append(const QByteArray &qba) {
-        buffers[tailBuffer].resize(tail);
-        buffers << qba;
-        ++tailBuffer;
+        if (tail == 0) {
+            buffers.last() = qba;
+        } else {
+            buffers.last().resize(tail);
+            buffers << qba;
+            ++tailBuffer;
+        }
         tail = qba.length();
         bufferSize += qba.length();
     }
diff --git a/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp b/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
index 285cc3042a..a2d686d5d8 100644
--- a/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
+++ b/tests/auto/corelib/tools/qringbuffer/tst_qringbuffer.cpp
@@ -54,6 +54,7 @@ private slots:
     void sizeWhenEmpty();
     void sizeWhenReservedAndChopped();
     void sizeWhenReserved();
+    void appendAndRead();
 };
 
 void tst_QRingBuffer::sizeWhenReserved()
@@ -179,6 +180,20 @@ void tst_QRingBuffer::readPointerAtPositionWriteRead()
     QVERIFY(outData.buffer().startsWith(inData.buffer()));
 }
 
+void tst_QRingBuffer::appendAndRead()
+{
+    QRingBuffer ringBuffer;
+    QByteArray ba1("Hello world!");
+    QByteArray ba2("Test string.");
+    QByteArray ba3("0123456789");
+    ringBuffer.append(ba1);
+    ringBuffer.append(ba2);
+    ringBuffer.append(ba3);
+
+    QVERIFY(ringBuffer.read() == ba1);
+    QVERIFY(ringBuffer.read() == ba2);
+    QVERIFY(ringBuffer.read() == ba3);
+}
 
 QTEST_APPLESS_MAIN(tst_QRingBuffer)
 #include "tst_qringbuffer.moc"