fix QProcess pipe deadlock: drain stdout in run9p while waiting

gui/ollie9pclient.cpp

@@ -241,6 +241,15 @@ QByteArray Ollie9pClient::run9p(const QStringList &args)
     QStringList fullArgs = {"-a", serverAddr()};
     fullArgs.append(args);
     proc.start(ninepBin(), fullArgs);
-    proc.waitForFinished(10000);
+
-    return proc.readAllStandardOutput();
+    // Drain output while waiting. The log file can be up to 64KB; if the
+    // parent doesn't read, the child blocks on a full pipe and never exits,
+    // causing "QProcess: Destroyed while process is still running".
+    QByteArray out;
+    while (proc.state() != QProcess::NotRunning) {
+        if (proc.waitForReadyRead(100))
+            out += proc.readAllStandardOutput();
+    }
+    out += proc.readAllStandardOutput();
+    return out;
 }