QDataStream doesn't check return values from QIODevice::write

QDataStream does not check values from QIODevice::write and QIODevice::read
since it cannot decide what to do in case of errors or less data written
or read. The fix for this is to fix the documentation for
QIODevice::writeData and QIODevice::readData to make sure implementations
write and read all the requested data.

Task-number: QTBUG-13108
Reviewed-by: David Boddie

1 files changed, 12 insertions, 0 deletions

diff --git a/src/corelib/io/qiodevice.cpp b/src/corelib/io/qiodevice.cpp
index 26e587d..8544fba 100644
--- a/src/corelib/io/qiodevice.cpp
+++ b/src/corelib/io/qiodevice.cpp
@@ -1633,6 +1633,12 @@ QString QIODevice::errorString() const
     This function is called by QIODevice. Reimplement this function
     when creating a subclass of QIODevice.
 
+    When reimplementing this function it is important that this function
+    reads all the required data before returning. This is required in order
+    for QDataStream to be able to operate on the class. QDataStream assumes
+    all the requested information was read and therefore does not retry reading
+    if there was a problem.
+
     \sa read() readLine() writeData()
 */
 
@@ -1645,6 +1651,12 @@ QString QIODevice::errorString() const
     This function is called by QIODevice. Reimplement this function
     when creating a subclass of QIODevice.
 
+    When reimplementing this function it is important that this function
+    writes all the data available before returning. This is required in order
+    for QDataStream to be able to operate on the class. QDataStream assumes
+    all the information was written and therefore does not retry writing if
+    there was a problem.
+
     \sa read() write()
 */