fix canReadLine() erroneously returning true

the indexOf() call did not consider actualReadBufferSize and thus
scanned uninitialized memory for newlines.

Reviewed-by: phartman

2 files changed, 29 insertions, 1 deletions

diff --git a/src/corelib/tools/qringbuffer_p.h b/src/corelib/tools/qringbuffer_p.h
index c44346c..7c766cb 100644
--- a/src/corelib/tools/qringbuffer_p.h
+++ b/src/corelib/tools/qringbuffer_p.h
@@ -287,6 +287,33 @@ public:
         return -1;
     }
 
+    inline int indexOf(char c, int maxLength) const {
+        int index = 0;
+        int remain = qMin(size(), maxLength);
+        for (int i = 0; remain && i < buffers.size(); ++i) {
+            int start = 0;
+            int end = buffers.at(i).size();
+
+            if (i == 0)
+                start = head;
+            if (i == tailBuffer)
+                end = tail;
+            if (remain < end - start) {
+                end = start + remain;
+                remain = 0;
+            } else {
+                remain -= end - start;
+            }
+            const char *ptr = buffers.at(i).data() + start;
+            for (int j = start; j < end; ++j) {
+                if (*ptr++ == c)
+                    return index;
+                ++index;
+            }
+        }
+        return -1;
+    }
+
     inline int read(char *data, int maxLength) {
         int bytesToRead = qMin(size(), maxLength);
         int readSoFar = 0;
diff --git a/src/network/socket/qlocalsocket_win.cpp b/src/network/socket/qlocalsocket_win.cpp
index 8a745ab..d812d88 100644
--- a/src/network/socket/qlocalsocket_win.cpp
+++ b/src/network/socket/qlocalsocket_win.cpp
@@ -363,7 +363,8 @@ bool QLocalSocket::canReadLine() const
     Q_D(const QLocalSocket);
     if (state() != ConnectedState)
         return false;
-    return (d->readBuffer.indexOf('\n') != -1 || QIODevice::canReadLine());
+    return (QIODevice::canReadLine()
+            || d->readBuffer.indexOf('\n', d->actualReadBufferSize) != -1);
 }
 
 void QLocalSocket::close()