One more improvement in QUrl: avoid an extra lowercasing step.

Since we're going to do nameprepping anyways, avoid the lowercasing
step at the function entry (and thus, one extra temporary). The
nameprepping step is also faster than QString::toLower for the ASCII
case.

1 files changed, 13 insertions, 17 deletions

diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index fcae0d6..fe3ad82 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -3178,7 +3178,7 @@ static bool qt_is_idn_enabled(const QString &domain)
     int len = domain.size() - idx - 1;
 
     if (user_idn_whitelist)
-        return user_idn_whitelist->contains(QString(tld, len));
+        return user_idn_whitelist->contains(QString::fromRawData(tld, len).toLower());
 
     int l = 0;
     int r = sizeof(idn_whitelist)/sizeof(const char *) - 1;
@@ -3217,11 +3217,10 @@ static int nextDotDelimiter(const QString &domain, int from = 0)
 }
 
 enum AceOperation { ToAceOnly, NormalizeAce };
-static QString qt_ACE_do(const QString &domainMC, AceOperation op)
+static QString qt_ACE_do(const QString &domain, AceOperation op)
 {
-    if (domainMC.isEmpty())
-        return domainMC;
-    QString domain = domainMC.toLower();
+    if (domain.isEmpty())
+        return domain;
 
     QString result;
     result.reserve(domain.length());
@@ -3255,30 +3254,27 @@ static QString qt_ACE_do(const QString &domainMC, AceOperation op)
             }
         }
 
+        // copy the label to the destination, which also serves as our scratch area
+        // then nameprep it (in the case of "simple", it will cause a simple lowercasing)
+        int prevLen = result.size();
+        result.resize(prevLen + idx - lastIdx);
+        memcpy(result.data() + prevLen, domain.constData() + lastIdx, (idx - lastIdx) * sizeof(QChar));
+        qt_nameprep(&result, prevLen);
+
         if (simple && idx > lastIdx + 4) {
-            // ACE form domains are simple, but we can't consider them simple
+            // ACE form domains contain only ASCII characters, but we can't consider them simple
             // is this an ACE form?
             static const ushort acePrefixUtf16[] = { 'x', 'n', '-', '-' };
-            if (memcmp(domain.utf16() + lastIdx, acePrefixUtf16, sizeof acePrefixUtf16) == 0)
+            if (memcmp(result.utf16() + prevLen, acePrefixUtf16, sizeof acePrefixUtf16) == 0)
                 simple = false;
         }
 
-        // copy the label to the destination, which also serves as our scratch area
-        int prevLen = result.size();
-        result.resize(prevLen + idx - lastIdx);
-        memcpy(result.data() + prevLen, domain.constData() + lastIdx, (idx - lastIdx) * sizeof(QChar));
-
         if (simple) {
             // fastest case: this is the common case (non IDN-domains)
-            // there's no need to nameprep since everything is ASCII already
             // so we're done
             if (!qt_check_std3rules(result.constData() + prevLen, result.length() - prevLen))
                 return QString();
         } else { 
-            // Nameprep the host. If the labels in the hostname are Punycode
-            // encoded, we decode them immediately.
-            qt_nameprep(&result, prevLen);
-
             // Punycode encoding and decoding cannot be done in-place
             // That means we need one or two temporaries
             QString aceForm;