Revert "Perforce: Allow working with localhost server"

It breaks the common use-case.

Running p4 client -o in any directory returns Host,
even if it is not managed by Perforce.

This reverts commit 28f7c7935f.

Fixes: QTCREATORBUG-22458
Change-Id: Iaa84ff68e2c6d807c6c177ff2113b07380b4e5be
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/perforce/perforcechecker.cpp

@@ -175,6 +175,17 @@ static inline QString clientRootFromOutput(const QString &in)
     return QString();
 }
 
+// When p4 port and p4 user is set a preconfigured Root: is given, which doesn't relate with
+// the current mapped project. In this case "Client:" has the same value as "Host:", which is an
+// invalid case.
+static inline bool clientAndHostAreEqual(const QString &in)
+{
+    QString client = findTerm(in, QLatin1String("Client:"));
+    QString host = findTerm(in, QLatin1String("Host:"));
+
+    return client == host;
+}
+
 void PerforceChecker::parseOutput(const QString &response)
 {
     if (!response.contains(QLatin1String("View:")) && !response.contains(QLatin1String("//depot/"))) {
@@ -182,6 +193,12 @@ void PerforceChecker::parseOutput(const QString &response)
         return;
     }
 
+    if (clientAndHostAreEqual(response)) {
+        // Is an invalid case. But not an error. QtC checks cmake install directories for
+        // p4 repositories, or the %temp% directory.
+        return;
+    }
+
     const QString repositoryRoot = clientRootFromOutput(response);
     if (repositoryRoot.isEmpty()) {
         //: Unable to determine root of the p4 client installation