From cdebc1a138eb4e4272b0b96e6bfce4fd66851ce1 Mon Sep 17 00:00:00 2001
From: Anton Kudryavtsev <anton.kudryavtsev@corp.mail.ru>
Date: Tue, 30 Jan 2018 19:57:28 +0300
Subject: [PATCH] QString: optimize remove()

In remove(const QString &str, Qt::CaseSensitivity cs)
call remove(QChar c, Qt::CaseSensitivity cs)
if str.size() is equal 1. It prevents quadratic behavior
for that case.

Change-Id: I9a7ab3019c580343533c8c6c6a04b6b0c8c1fb55
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/tools/qstring.cpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/corelib/tools/qstring.cpp b/src/corelib/tools/qstring.cpp
index 69751eb6dc..4e7baa18b6 100644
--- a/src/corelib/tools/qstring.cpp
+++ b/src/corelib/tools/qstring.cpp
@@ -2599,10 +2599,15 @@ QString &QString::remove(int pos, int len)
 */
 QString &QString::remove(const QString &str, Qt::CaseSensitivity cs)
 {
-    if (str.d->size) {
-        int i = 0;
-        while ((i = indexOf(str, i, cs)) != -1)
-            remove(i, str.d->size);
+    const int strSize = str.size();
+    if (strSize) {
+        if (strSize == 1) {
+            remove(str.front(), cs);
+        } else {
+            int i = 0;
+            while ((i = indexOf(str, i, cs)) != -1)
+                remove(i, strSize);
+        }
     }
     return *this;
 }