1 files changed, 75 insertions, 0 deletions

diff --git a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
index 72a6427930..fc7247b733 100644
--- a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
+++ b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
@@ -35,6 +35,7 @@
 #include <limits.h>
 #include <private/qtools_p.h>
 
+#include <iterator>
 #include <stdexcept>
 #include <string_view>
 
@@ -53,6 +54,7 @@ private slots:
     void qCompress();
     void qUncompressCorruptedData_data();
     void qUncompressCorruptedData();
+    void qUncompress4GiBPlus();
     void qCompressionZeroTermination();
 #endif
     void constByteArray();
@@ -343,6 +345,79 @@ void tst_QByteArray::qUncompressCorruptedData()
 #endif
 }
 
+void tst_QByteArray::qUncompress4GiBPlus()
+{
+    // after three rounds, this decompresses to 4GiB + 1 'X' bytes:
+    constexpr uchar compressed_3x[] = {
+       0x00, 0x00, 0x1a, 0x76, 0x78, 0x9c, 0x63, 0xb0, 0xdf, 0xb4, 0xad, 0x62,
+       0xce, 0xdb, 0x3b, 0x0b, 0xf3, 0x26, 0x27, 0x4a, 0xb4, 0x3d, 0x34, 0x5b,
+       0xed, 0xb4, 0x41, 0xf1, 0xc0, 0x99, 0x2f, 0x02, 0x05, 0x67, 0x26, 0x88,
+       0x6c, 0x66, 0x71, 0x34, 0x62, 0x9c, 0x75, 0x26, 0xb1, 0xa0, 0xe5, 0xcc,
+       0xda, 0x94, 0x83, 0xc9, 0x05, 0x73, 0x0e, 0x3c, 0x39, 0xc2, 0xc7, 0xd0,
+       0xae, 0x38, 0x53, 0x7b, 0x87, 0xdc, 0x01, 0x91, 0x45, 0x59, 0x4f, 0xda,
+       0xbf, 0xca, 0xcc, 0x52, 0xdb, 0xbb, 0xde, 0xbb, 0xf6, 0xd3, 0x55, 0xff,
+       0x7d, 0x77, 0x0e, 0x1b, 0xf0, 0xa4, 0xdf, 0xcf, 0xdb, 0x5f, 0x2f, 0xf5,
+       0xd7, 0x7c, 0xfe, 0xbf, 0x3f, 0xbf, 0x3f, 0x9d, 0x7c, 0xda, 0x2c, 0xc8,
+       0xc0, 0xc0, 0xb0, 0xe1, 0xf1, 0xb3, 0xfd, 0xfa, 0xdf, 0x8e, 0x7d, 0xef,
+       0x7f, 0xb9, 0xc1, 0xc2, 0xae, 0x92, 0x19, 0x28, 0xf2, 0x66, 0xd7, 0xe5,
+       0xbf, 0xed, 0x93, 0xbf, 0x6a, 0x14, 0x7c, 0xff, 0xf6, 0xe1, 0xe8, 0xb6,
+       0x7e, 0x46, 0xa0, 0x90, 0xd9, 0xbb, 0xcf, 0x9f, 0x17, 0x37, 0x7f, 0xe5,
+       0x6f, 0xb4, 0x7f, 0xfe, 0x5e, 0xfd, 0xb6, 0x1d, 0x1b, 0x50, 0xe8, 0xc6,
+       0x8e, 0xe3, 0xab, 0x9f, 0xe6, 0xec, 0x65, 0xfd, 0x23, 0xb1, 0x4e, 0x7e,
+       0xef, 0xbd, 0x6f, 0xa6, 0x40, 0xa1, 0x03, 0xc7, 0xfe, 0x0a, 0xf1, 0x00,
+       0xe9, 0x06, 0x91, 0x83, 0x40, 0x92, 0x21, 0x43, 0x10, 0xcc, 0x11, 0x03,
+       0x73, 0x3a, 0x90, 0x39, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32,
+       0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32,
+       0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32,
+       0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32,
+       0xa3, 0x32, 0xa3, 0x32, 0xa3, 0x32, 0x34, 0x90, 0x99, 0xb6, 0x7e, 0xf5,
+       0xd3, 0xe9, 0xbf, 0x35, 0x13, 0xca, 0x8c, 0x75, 0xec, 0xec, 0xa4, 0x2f,
+       0x7e, 0x2d, 0xf9, 0xf3, 0xf0, 0xee, 0xea, 0xd5, 0xf5, 0xd3, 0x14, 0x57,
+       0x06, 0x00, 0x00, 0xb9, 0x1e, 0x35, 0xce
+    };
+
+    constexpr qint64 GiB = 1024LL * 1024 * 1024;
+
+    if constexpr (sizeof(qsizetype) == sizeof(int)) {
+        QSKIP("This is a 64-bit-only test.");
+    } else {
+
+        // 1st
+        auto c = ::qUncompress(std::data(compressed_3x), qsizetype(std::size(compressed_3x)));
+        QVERIFY(!c.isNull()); // check for decompression error
+
+        // 2nd
+        c = ::qUncompress(c);
+        QVERIFY(!c.isNull());
+
+        // 3rd
+        try {
+            c = ::qUncompress(c);
+            if (c.isNull())  // this step (~18MiB -> 4GiB) might have run out of memory
+                QSKIP("Failed to allocate enough memory.");
+        } catch (const std::bad_alloc &) {
+            QSKIP("Failed to allocate enough memory.");
+        }
+
+        QCOMPARE(c.size(), 4 * GiB + 1);
+        QCOMPARE(std::string_view{c}.find_first_not_of('X'),
+                 std::string_view::npos);
+
+        // re-compress once
+        // (produces 18MiB, we shouldn't use much more than that in allocated capacity)
+        c = ::qCompress(c);
+        QVERIFY(!c.isNull());
+
+        // and un-compress again, to make sure compression worked (we
+        // can't compare with compressed_3x, because zlib may change):
+        c = ::qUncompress(c);
+
+        QCOMPARE(c.size(), 4 * GiB + 1);
+        QCOMPARE(std::string_view{c}.find_first_not_of('X'),
+                 std::string_view::npos);
+    }
+}
+
 void tst_QByteArray::qCompressionZeroTermination()
 {
     QString s = "Hello, I'm a string.";