Always use fast path in QString::append(QLatin1String)

This must be possible with a new set of changes and the way QString
reallocates

Task-number: QTBUG-86583
Change-Id: I513f51d7c6e984ae4e81fc344138687c791037c4
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 4 insertions, 7 deletions

diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 1f32c4db7d..32e5bb7b20 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -2835,13 +2835,10 @@ QString &QString::append(QLatin1String str)
         if (d->needsDetach() || str.size() > d->freeSpaceAtEnd())
             reallocGrowData(len);
 
-        if (d.freeSpaceAtBegin() == 0) {  // fast path
-            char16_t *i = d.data() + d.size;
-            qt_from_latin1(i, s, size_t(len));
-            d.size += len;
-        } else {  // slow path
-            d->copyAppend(s, s + len);
-        }
+        Q_ASSERT(str.size() <= d->freeSpaceAtEnd());
+        char16_t *i = d.data() + d.size;
+        qt_from_latin1(i, s, size_t(len));
+        d.size += len;
         d.data()[d.size] = '\0';
     }
     return *this;