diff options
| -rw-r--r-- | src/corelib/io/qfsfileengine.cpp | 46 |
1 files changed, 25 insertions, 21 deletions
diff --git a/src/corelib/io/qfsfileengine.cpp b/src/corelib/io/qfsfileengine.cpp index 429c40da1a..10e116a23a 100644 --- a/src/corelib/io/qfsfileengine.cpp +++ b/src/corelib/io/qfsfileengine.cpp @@ -724,29 +724,33 @@ qint64 QFSFileEnginePrivate::writeFdFh(const char *data, qint64 len) qint64 writtenBytes = 0; - if (fh) { - // Buffered stdlib mode. - - size_t result; - do { - result = fwrite(data + writtenBytes, 1, size_t(len - writtenBytes), fh); - writtenBytes += result; - } while (result == 0 ? errno == EINTR : writtenBytes < len); + if (len) { // avoid passing nullptr to fwrite() or QT_WRITE() (UB) - } else if (fd != -1) { - // Unbuffered stdio mode. + if (fh) { + // Buffered stdlib mode. + + size_t result; + do { + result = fwrite(data + writtenBytes, 1, size_t(len - writtenBytes), fh); + writtenBytes += result; + } while (result == 0 ? errno == EINTR : writtenBytes < len); + + } else if (fd != -1) { + // Unbuffered stdio mode. + + SignedIOType result; + do { + // calculate the chunk size + // on Windows or 32-bit no-largefile Unix, we'll need to read in chunks + // we limit to the size of the signed type, otherwise we could get a negative number as a result + quint64 wantedBytes = quint64(len) - quint64(writtenBytes); + UnsignedIOType chunkSize = std::numeric_limits<SignedIOType>::max(); + if (chunkSize > wantedBytes) + chunkSize = wantedBytes; + result = QT_WRITE(fd, data + writtenBytes, chunkSize); + } while (result > 0 && (writtenBytes += result) < len); + } - SignedIOType result; - do { - // calculate the chunk size - // on Windows or 32-bit no-largefile Unix, we'll need to read in chunks - // we limit to the size of the signed type, otherwise we could get a negative number as a result - quint64 wantedBytes = quint64(len) - quint64(writtenBytes); - UnsignedIOType chunkSize = std::numeric_limits<SignedIOType>::max(); - if (chunkSize > wantedBytes) - chunkSize = wantedBytes; - result = QT_WRITE(fd, data + writtenBytes, chunkSize); - } while (result > 0 && (writtenBytes += result) < len); } if (len && writtenBytes == 0) { |