Cmake: Fix autodetection of cmake on Windows

By using some of the infrastructure in Utils::Environment. Due to
wanting to find all cmake executables in PATH and not just the
first one, we need some custom code.

(cherry picked from commit ca8b43f6

)
Change-Id: If3161d712b9f6e659450a3d0647f83344e68ba5d
Task-number: QTCREATORBUG-14740
Reviewed-by: Robert Loehning <robert.loehning@theqtcompany.com>
Reviewed-by: Daniel Teske <daniel.teske@theqtcompany.com>

src/libs/utils/environment.cpp

@@ -233,36 +233,40 @@ FileName Environment::searchInDirectory(const QStringList &execs, QString direct
     return FileName();
 }
 
-FileName Environment::searchInPath(const QString &executable,
-                                   const QStringList &additionalDirs) const
+QStringList Environment::appendExeExtensions(const QString &executable) const
 {
-    if (executable.isEmpty())
-        return FileName();
-
-    QString exec = QDir::cleanPath(expandVariables(executable));
-    QFileInfo fi(exec);
-
-    QStringList execs(exec);
+    QFileInfo fi(executable);
+    QStringList execs(executable);
     if (m_osType == OsTypeWindows) {
         // Check all the executable extensions on windows:
         // PATHEXT is only used if the executable has no extension
         if (fi.suffix().isEmpty()) {
             QStringList extensions = value(QLatin1String("PATHEXT")).split(QLatin1Char(';'));
 
-            foreach (const QString &ext, extensions) {
-                QString tmp = executable + ext.toLower();
-                if (fi.isAbsolute()) {
-                    if (QFile::exists(tmp))
-                        return FileName::fromString(tmp);
-                } else {
-                    execs << tmp;
-                }
-            }
+            foreach (const QString &ext, extensions)
+                execs << executable + ext.toLower();
         }
     }
+    return execs;
+}
 
-    if (fi.isAbsolute())
+FileName Environment::searchInPath(const QString &executable,
+                                   const QStringList &additionalDirs) const
+{
+    if (executable.isEmpty())
+        return FileName();
+
+    QString exec = QDir::cleanPath(expandVariables(executable));
+    QFileInfo fi(exec);
+
+    QStringList execs = appendExeExtensions(exec);
+
+    if (fi.isAbsolute()) {
+        foreach (const QString &path, execs)
+            if (QFile::exists(path))
+                return FileName::fromString(path);
         return FileName::fromString(exec);
+    }
 
     QSet<QString> alreadyChecked;
     foreach (const QString &dir, additionalDirs) {

src/libs/utils/environment.h

@@ -105,6 +105,7 @@ public:
     FileName searchInPath(const QString &executable,
                           const QStringList &additionalDirs = QStringList()) const;
     QStringList path() const;
+    QStringList appendExeExtensions(const QString &executable) const;
 
     QString expandVariables(const QString &input) const;
     QStringList expandVariables(const QStringList &input) const;

src/plugins/cmakeprojectmanager/cmaketoolmanager.cpp

@@ -163,20 +163,29 @@ static void readAndDeleteLegacyCMakeSettings ()
 
 static QList<CMakeTool *> autoDetectCMakeTools()
 {
-    QStringList filters;
-    filters.append(QStringLiteral("cmake"));
-
     QList<FileName> suspects;
 
-    QStringList path = Environment::systemEnvironment().path();
+    Utils::Environment env = Environment::systemEnvironment();
+
+    QStringList path = env.path();
     path.removeDuplicates();
-    QDir dir;
-    dir.setNameFilters(filters);
-    dir.setFilter(QDir::Files | QDir::Executable);
-    foreach (const QString &base, path) {
-        dir.setPath(base);
-        foreach (const QString &entry, dir.entryList())
-            suspects.append(FileName::fromString(dir.absoluteFilePath(entry)));
+
+    QStringList execs = env.appendExeExtensions(QLatin1String("cmake"));
+
+    foreach (QString base, path) {
+        const QChar slash = QLatin1Char('/');
+        if (base.isEmpty())
+            continue;
+        // Avoid turning '/' into '//' on Windows which triggers Windows to check
+        // for network drives!
+        if (!base.endsWith(slash))
+            base += slash;
+
+        foreach (const QString &exec, execs) {
+            QFileInfo fi(base + exec);
+            if (fi.exists() && fi.isFile() && fi.isExecutable())
+                suspects << FileName::fromString(fi.absoluteFilePath());
+        }
     }
 
     QList<CMakeTool *> found;