Fix handling of IPv6 addresses in QUrl::fromUserInput

IPv6 addresses can start with ":", for which QDir::isAbsolute() would
always return true (QResourceFileEngine::isRelativePath() returns
constant false) and would trip the calculation for local files.

Similarly, IPv6 addresses can start with strings that look like Windows
drives: "a:", "b:", "c:", "d:", "e:" and "f:" (though not today, as
those address blocks are unassigned). Since a valid IPv6 address will
definitely require at least one more colon and Windows file names cannot
contain ':', there's no ambiguity: a valid IPv6 address is never a valid
file on Windows.

This resolves the ambiguity in favor of IPv6 for Unix filenames (which
can contain a colon) and in case of an URL containing scheme, relative
path and no authority ("dead:beef::" for example could have been parsed
as scheme() == "dead" and path() == "beef::").

Task-number: QTBUG-41089
Change-Id: Id9119af1acf8a75a786519af3b48b4ca3dbf3719
Reviewed-by: David Faure <david.faure@kdab.com>

1 files changed, 25 insertions, 1 deletions

diff --git a/src/corelib/io/qurl.cpp b/src/corelib/io/qurl.cpp
index 252b21032e..d4c5e03058 100644
--- a/src/corelib/io/qurl.cpp
+++ b/src/corelib/io/qurl.cpp
@@ -4079,6 +4079,11 @@ static QUrl adjustFtpPath(QUrl url)
     return url;
 }
 
+static bool isIp6(const QString &text)
+{
+    QIPAddressUtils::IPv6Address address;
+    return !text.isEmpty() && QIPAddressUtils::parseIp6(address, text.begin(), text.end()) == 0;
+}
 
 // The following code has the following copyright:
 /*
@@ -4135,8 +4140,18 @@ QUrl QUrl::fromUserInput(const QString &userInput, const QString &workingDirecto
     if (trimmedString.isEmpty())
         return QUrl();
 
-    // Check both QUrl::isRelative (to detect full URLs) and QDir::isAbsolutePath (since on Windows drive letters can be interpreted as schemes)
+
+    // Check for IPv6 addresses, since a path starting with ":" is absolute (a resource)
+    // and IPv6 addresses can start with "c:" too
+    if (isIp6(trimmedString)) {
+        QUrl url;
+        url.setHost(trimmedString);
+        url.setScheme(QStringLiteral("http"));
+        return url;
+    }
+
     QUrl url = QUrl(trimmedString, QUrl::TolerantMode);
+    // Check both QUrl::isRelative (to detect full URLs) and QDir::isAbsolutePath (since on Windows drive letters can be interpreted as schemes)
     if (url.isRelative() && !QDir::isAbsolutePath(trimmedString)) {
         QFileInfo fileInfo(QDir(workingDirectory), trimmedString);
         if ((options & AssumeLocalFile) || fileInfo.exists())
@@ -4181,6 +4196,15 @@ QUrl QUrl::fromUserInput(const QString &userInput)
 {
     QString trimmedString = userInput.trimmed();
 
+    // Check for IPv6 addresses, since a path starting with ":" is absolute (a resource)
+    // and IPv6 addresses can start with "c:" too
+    if (isIp6(trimmedString)) {
+        QUrl url;
+        url.setHost(trimmedString);
+        url.setScheme(QStringLiteral("http"));
+        return url;
+    }
+
     // Check first for files, since on Windows drive letters can be interpretted as schemes
     if (QDir::isAbsolutePath(trimmedString))
         return QUrl::fromLocalFile(trimmedString);