Merge branch 'jb49640_jb49699' into 'master'

Allow setting UserInfo by uid and update UserInfo if changes happen

See merge request mer-core/nemo-qml-plugin-systemsettings!142

src/userinfo.cpp

@@ -33,6 +33,8 @@
 #include "userinfo_p.h"
 #include "logging_p.h"
 
+#include <QFile>
+#include <QFileSystemWatcher>
 #include <QSocketNotifier>
 #include <poll.h>
 #include <pwd.h>
@@ -41,6 +43,8 @@
 
 namespace {
 
+const auto UserDatabaseFile = QStringLiteral("/etc/passwd");
+
 enum SpecialIds : uid_t {
     DeviceOwnerId = 100000,
     UnknownCurrentUserId = (uid_t)(-2),
@@ -65,6 +69,7 @@ QString nameFromGecos(const char *gecos)
 UserInfoPrivate::UserInfoPrivate()
     : m_uid(InvalidId)
     , m_loggedIn(false)
+    , m_watcher(nullptr)
 {
 }
 
@@ -76,6 +81,7 @@ UserInfoPrivate::UserInfoPrivate(struct passwd *pwd)
     // Specifying seat should make sure that remote users are not
     // counted as they don't have seats.
     , m_loggedIn(sd_uid_is_on_seat(m_uid, 1, "seat0") > 0)
+    , m_watcher(nullptr)
 {
 }
 
@@ -143,10 +149,11 @@ UserInfo::UserInfo()
             waitForActivation();
         }
         // pwd must not be free'd
+        if (current())
+            UserInfoPrivate::s_current = d_ptr;
     }
-    if (current())
-        UserInfoPrivate::s_current = d_ptr;
     connectSignals();
+    watchForChanges();
 }
 
 UserInfo::UserInfo(const UserInfo &other)
@@ -161,15 +168,20 @@ UserInfo::UserInfo(const UserInfo &other)
  */
 UserInfo::UserInfo(int uid)
 {
-    struct passwd *pwd = (uid_t)uid != InvalidId ? getpwuid((uid_t)uid) : nullptr;
-    if (pwd) {
-        d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate(pwd));
+    auto current_d = UserInfoPrivate::s_current.toStrongRef();
+    if (!current_d.isNull() && current_d->m_uid == (uid_t)uid) {
+        d_ptr = current_d;
     } else {
-        d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate);
+        struct passwd *pwd = (uid_t)uid != InvalidId ? getpwuid((uid_t)uid) : nullptr;
+        if (pwd) {
+            d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate(pwd));
+        } else {
+            d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate);
+        }
+        // pwd must not be free'd
+        if (current())
+            UserInfoPrivate::s_current = d_ptr;
     }
-    // pwd must not be free'd
-    if (current())
-        UserInfoPrivate::s_current = d_ptr;
     connectSignals();
 }
 
@@ -178,15 +190,20 @@ UserInfo::UserInfo(int uid)
  */
 UserInfo::UserInfo(QString username)
 {
-    struct passwd *pwd = getpwnam(username.toUtf8().constData());
-    if (pwd) {
-        d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate(pwd));
+    auto current_d = UserInfoPrivate::s_current.toStrongRef();
+    if (!current_d.isNull() && current_d->m_username == username) {
+        d_ptr = current_d;
     } else {
-        d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate);
+        struct passwd *pwd = getpwnam(username.toUtf8().constData());
+        if (pwd) {
+            d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate(pwd));
+        } else {
+            d_ptr = QSharedPointer<UserInfoPrivate>(new UserInfoPrivate);
+        }
+        // pwd must not be free'd
+        if (current())
+            UserInfoPrivate::s_current = d_ptr;
     }
-    // pwd must not be free'd
-    if (current())
-        UserInfoPrivate::s_current = d_ptr;
     connectSignals();
 }
 
@@ -275,6 +292,13 @@ int UserInfo::uid() const
     return (int)d->m_uid;
 }
 
+void UserInfo::setUid(int uid)
+{
+    Q_D(const UserInfo);
+    if ((uid_t)uid != d->m_uid)
+        replace(UserInfo(uid).d_ptr);
+}
+
 /**
  * Returs true if user is logged in on seat0 and is the active user, i.e. the current user
  */
@@ -312,6 +336,7 @@ void UserInfo::reset()
 void UserInfo::replace(QSharedPointer<UserInfoPrivate> other)
 {
     auto old = d_ptr;
+    disconnect(old.data(), 0, this, 0);
     d_ptr = other;
 
     if (old->m_username != d_ptr->m_username) {
@@ -331,6 +356,11 @@ void UserInfo::replace(QSharedPointer<UserInfoPrivate> other)
 
     if (old->m_loggedIn != d_ptr->m_loggedIn)
         emit currentChanged();
+
+    if (old->m_watcher)
+        watchForChanges();
+
+    connectSignals();
 }
 
 UserInfo &UserInfo::operator=(const UserInfo &other)
@@ -366,6 +396,33 @@ void UserInfo::connectSignals()
     connect(d_ptr.data(), &UserInfoPrivate::currentChanged, this, &UserInfo::currentChanged);
 }
 
+void UserInfo::watchForChanges()
+{
+    Q_D(UserInfo);
+    d->m_watcher = new QFileSystemWatcher(this);
+    if (!d->m_watcher->addPath(UserDatabaseFile)) {
+        qCWarning(lcUsersLog) << "Could not watch for changes in user database";
+        delete d->m_watcher;
+        d->m_watcher = nullptr;
+    } else {
+        connect(d->m_watcher, &QFileSystemWatcher::fileChanged, this, [this] {
+            Q_D(UserInfo);
+            if (QFile::exists(UserDatabaseFile)) {
+                // Database updated, reset
+                qCDebug(lcUsersLog) << "Reseting model because user database changed";
+                reset();
+            }
+            if (!d->m_watcher->files().contains(UserDatabaseFile)) {
+                if (QFile::exists(UserDatabaseFile) && d->m_watcher->addPath(UserDatabaseFile)) {
+                    qCDebug(lcUsersLog) << "Re-watching user database for changes";
+                } else {
+                    qCWarning(lcUsersLog) << "Stopped watching user database for changes";
+                }
+            }
+        });
+    }
+}
+
 void UserInfo::waitForActivation()
 {
     // Monitor systemd-logind for changes on seats

src/userinfo.h

@@ -50,7 +50,7 @@ class SYSTEMSETTINGS_EXPORT UserInfo: public QObject
     Q_PROPERTY(QString username READ username NOTIFY usernameChanged)
     Q_PROPERTY(QString name READ name NOTIFY nameChanged)
     Q_PROPERTY(UserType type READ type CONSTANT)
-    Q_PROPERTY(int uid READ uid NOTIFY uidChanged)
+    Q_PROPERTY(int uid READ uid WRITE setUid NOTIFY uidChanged)
     Q_PROPERTY(bool current READ current NOTIFY currentChanged)
 
     friend class UserModel;
@@ -75,6 +75,7 @@ class SYSTEMSETTINGS_EXPORT UserInfo: public QObject
     QString name() const;
     UserType type() const;
     int uid() const;
+    void setUid(int uid);
     bool current() const;
 
     Q_INVOKABLE void reset();
@@ -100,6 +101,7 @@ class SYSTEMSETTINGS_EXPORT UserInfo: public QObject
     void replace(QSharedPointer<UserInfoPrivate> other);
 
     void connectSignals();
+    void watchForChanges();
     void waitForActivation();
 
     QSharedPointer<UserInfoPrivate> d_ptr;

src/userinfo_p.h

@@ -38,6 +38,8 @@
 #include <QString>
 #include <QWeakPointer>
 
+class QFileSystemWatcher;
+
 class UserInfoPrivate : public QObject
 {
     Q_OBJECT
@@ -52,6 +54,7 @@ class UserInfoPrivate : public QObject
     QString m_name;
     bool m_loggedIn;
     static QWeakPointer<UserInfoPrivate> s_current;
+    QFileSystemWatcher *m_watcher;
 
     void set(struct passwd *pwd);