QHash: remove the ability to set a non-zero global seed

We've been warning since commit 4ba740b3bac6e1824c18614f579d106eee930d42
(2017-03-31, Qt 5.9.0).

Change-Id: Id2983978ad544ff79911fffd1671f505fee6f282
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 5 insertions, 6 deletions

diff --git a/src/corelib/tools/qhash.cpp b/src/corelib/tools/qhash.cpp
index 51e2a18961..23eb07406c 100644
--- a/src/corelib/tools/qhash.cpp
+++ b/src/corelib/tools/qhash.cpp
@@ -1,7 +1,7 @@
 /****************************************************************************
 **
 ** Copyright (C) 2020 The Qt Company Ltd.
-** Copyright (C) 2016 Intel Corporation.
+** Copyright (C) 2021 Intel Corporation.
 ** Copyright (C) 2012 Giuseppe D'Angelo <dangelog@gmail.com>.
 ** Contact: https://www.qt.io/licensing/
 **
@@ -725,8 +725,8 @@ static uint qt_create_qhash_seed()
         uint seed = envSeed.toUInt();
         if (seed) {
             // can't use qWarning here (reentrancy)
-            fprintf(stderr, "QT_HASH_SEED: forced seed value is not 0, cannot guarantee that the "
-                     "hashing functions will produce a stable value.");
+            fprintf(stderr, "QT_HASH_SEED: forced seed value is not 0; ignored.\n");
+            seed = 0;
         }
         return seed;
     }
@@ -812,10 +812,9 @@ void qSetGlobalQHashSeed(int newSeed)
     } else {
         if (newSeed) {
             // can't use qWarning here (reentrancy)
-            fprintf(stderr, "qSetGlobalQHashSeed: forced seed value is not 0, cannot guarantee that the "
-                            "hashing functions will produce a stable value.");
+            fprintf(stderr, "qSetGlobalQHashSeed: forced seed value is not 0; ignoring call\n");
         }
-        qt_qhash_seed.storeRelaxed(newSeed & INT_MAX);
+        qt_qhash_seed.storeRelaxed(0);
     }
 }