WinRT: fix hanging synthesize when RIFF header is removed

Amends 428cae98619584a51c01be135fecf6b347c117b3. If we drop the RIFF
header bytes, then we have fewer bytes available as well, so decrease
that value. Otherwise we never fetch more data.

Improve the test, which should have caught this regression, by testing
that synthesise cycles correctly through the states even if no default
audio output is present. The test was completely skipped because of
that, not detecting the regression.

Fixes: QTBUG-118668
Pick-to: 6.6
Change-Id: I3b4276c13ce2c77ec718d1b7bbca6f3421636890
Reviewed-by: Jarkko Koivikko <jarkko.koivikko@code-q.fi>

2 files changed, 25 insertions, 19 deletions

diff --git a/src/plugins/tts/winrt/qtexttospeech_winrt_audiosource.cpp b/src/plugins/tts/winrt/qtexttospeech_winrt_audiosource.cpp
index 476bc15..e71f112 100644
--- a/src/plugins/tts/winrt/qtexttospeech_winrt_audiosource.cpp
+++ b/src/plugins/tts/winrt/qtexttospeech_winrt_audiosource.cpp
@@ -107,7 +107,7 @@ qint64 AudioSource::readData(char *data, qint64 maxlen)
 
     Q_ASSERT(bufferByteAccess);
 
-    const qint64 available = bytesInBuffer();
+    qint64 available = bytesInBuffer();
     maxlen = qMin(available, maxlen);
 
     if (!maxlen && atEnd())
@@ -127,6 +127,7 @@ qint64 AudioSource::readData(char *data, qint64 maxlen)
             pbyte += WaveHeaderLength;
             m_bufferOffset += WaveHeaderLength;
             maxlen -= WaveHeaderLength;
+            available -= WaveHeaderLength;
         }
     }
 
diff --git a/tests/auto/qtexttospeech/tst_qtexttospeech.cpp b/tests/auto/qtexttospeech/tst_qtexttospeech.cpp
index 3e63d59..b2b8fb8 100644
--- a/tests/auto/qtexttospeech/tst_qtexttospeech.cpp
+++ b/tests/auto/qtexttospeech/tst_qtexttospeech.cpp
@@ -901,11 +901,10 @@ void tst_QTextToSpeech::synthesize_data()
 void tst_QTextToSpeech::synthesize()
 {
     QFETCH_GLOBAL(QString, engine);
-    if (engine != "mock" && !hasDefaultAudioOutput())
-        QSKIP("No audio device present");
-
     QFETCH(QString, text);
 
+    const bool canCheckDuration = engine == "mock" || hasDefaultAudioOutput();
+
     QTextToSpeech tts(engine);
     if (!(tts.engineCapabilities() & QTextToSpeech::Capability::Synthesize))
         QSKIP("This engine doesn't support synthesize()");
@@ -935,13 +934,15 @@ void tst_QTextToSpeech::synthesize()
         }
     });
 
-    // first, measure how long it takes to speak the text
-    tts.say(text);
-    QTRY_VERIFY(running);
-    QTRY_VERIFY(finished);
+    // first, measure how long it takes to speak the text. We can't do that if we
+    // can't play audio.
+    if (canCheckDuration) {
+        tts.say(text);
+        QTRY_VERIFY(running);
+        QTRY_VERIFY(finished);
+    }
 
     running = false;
-
     QAudioFormat pcmFormat;
     QByteArray pcmData;
 
@@ -956,16 +957,20 @@ void tst_QTextToSpeech::synthesize()
     QTRY_VERIFY(finished);
 
     QVERIFY(pcmFormat.isValid());
-    // bytesForDuration takes micro seconds, we measured in milliseconds.
-    const qint32 bytesExpected = pcmFormat.bytesForDuration(speechTime * 1000);
-
-    // We should have as much data as the format requires for the time it took
-    // to play the speech, +/- 10% as we can't measure the exact audio duration.
-    QCOMPARE_GE(pcmData.size(), double(bytesExpected) * 0.9);
-    if (engine == "flite") // flite is very unreliable
-        QCOMPARE_LT(pcmData.size(), double(bytesExpected) * 1.5);
-    else
-        QCOMPARE_LT(pcmData.size(), double(bytesExpected) * 1.1);
+    QVERIFY(!pcmData.isEmpty());
+
+    if (canCheckDuration) {
+        // bytesForDuration takes micro seconds, we measured in milliseconds.
+        const qint32 bytesExpected = pcmFormat.bytesForDuration(speechTime * 1000);
+
+        // We should have as much data as the format requires for the time it took
+        // to play the speech, +/- 10% as we can't measure the exact audio duration.
+        QCOMPARE_GE(pcmData.size(), double(bytesExpected) * 0.9);
+        if (engine == "flite") // flite is very unreliable
+            QCOMPARE_LT(pcmData.size(), double(bytesExpected) * 1.5);
+        else
+            QCOMPARE_LT(pcmData.size(), double(bytesExpected) * 1.1);
+    }
 }
 
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