Make QRingBuffer a 64-bit safe

According to I/O API, QIODevice and its inherited classes should be
able to process a full 64-bit offsets and lengths. This requires
64-bit parameters in operations with internal buffers. Rework
QRingBuffer to avoid implicit truncation of numbers and fix some
64-bit issues in code.

Change-Id: Iadd6fd5fefd2d64e6c084e2feebb4dc2d6df66de
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 6451bae0ba..d5c861f9ad 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -1912,12 +1912,12 @@ qint64 QProcess::readData(char *data, qint64 maxlen)
         return 1;
     }
 
-    qint64 bytesToRead = qint64(qMin(readBuffer->size(), (int)maxlen));
+    qint64 bytesToRead = qMin(readBuffer->size(), maxlen);
     qint64 readSoFar = 0;
     while (readSoFar < bytesToRead) {
         const char *ptr = readBuffer->readPointer();
-        int bytesToReadFromThisBlock = qMin<qint64>(bytesToRead - readSoFar,
-                                            readBuffer->nextDataBlockSize());
+        qint64 bytesToReadFromThisBlock = qMin(bytesToRead - readSoFar,
+                                               readBuffer->nextDataBlockSize());
         memcpy(data + readSoFar, ptr, bytesToReadFromThisBlock);
         readSoFar += bytesToReadFromThisBlock;
         readBuffer->free(bytesToReadFromThisBlock);