refact: add some checks

Signed-off-by: ComixHe <heyuming@deepin.org>

src/cgroupsidentifier.cpp

@@ -60,12 +60,22 @@ QString CGroupsIdentifier::parseCGroupsPath(QFile &cgroupFile) noexcept
     }
 
     auto CGPSlices = CGP.split('/', Qt::SkipEmptyParts);
+    if (CGPSlices.isEmpty()) {
+        qCritical() << "invalid cgroups path,abort.";
+        return {};
+    }
 
     if (CGPSlices.first() != "user.slice") {
         qWarning() << "unrecognized process.";
         return {};
     }
-    auto processUIDStr = CGPSlices[1].split('.').first().split('-').last();
+
+    auto userSlice = CGPSlices.at(1);
+    if (userSlice.isEmpty()) {
+        qWarning() << "couldn't detect uid.";
+        return {};
+    }
+    auto processUIDStr = userSlice.split('.').first().split('-').last();
 
     if (processUIDStr.isEmpty()) {
         qWarning() << "no uid found.";

src/dbus/applicationservice.cpp

@@ -863,7 +863,7 @@ LaunchTask ApplicationService::unescapeExec(const QString &str, const QStringLis
     }
 
     auto list = matcher.capturedTexts();
-    if (list.count() > 1) {
+    if (list.count() != 1) {
         qWarning() << "invalid exec format, all filed code will be ignored.";
         for (const auto &code : list) {
             execList.removeOne(code);

src/global.h

@@ -473,6 +473,10 @@ inline QString getCurrentDesktop()
         qWarning() << "multi-DE is detected, use first value.";
     }
 
+    if (desktops.isEmpty()) {
+        return "DDE";
+    }
+
     return desktops.first();
 }