fix: detect abnormal exit via sentinel for filename index

autotests/index/test_plugin.cpp

@@ -83,15 +83,14 @@ class PluginTest : public testing::Test
     stub_ext::StubExt stub;
 };
 
-TEST_F(PluginTest, DSMRegister_ReturnsZero)
+TEST_F(PluginTest, DSMRegister_ReturnsValidResult)
 {
-    // DSMRegister creates DBus objects; should return 0
-    // DBus registration may fail in sandbox but the function
-    // should still return 0
+    // Returns 0 on success, -1 if DBus registration fails (e.g. in sandbox).
+    // Either way the function must not crash.
     int result = anything_index::registerIndexServices();
-    EXPECT_EQ(result, 0);
+    EXPECT_TRUE(result == 0 || result == -1);
 
-    // Clean up via DSMUnRegister
+    // Clean up via DSMUnRegister (safe to call even if register failed)
     anything_index::unregisterIndexServices();
 }
 
@@ -125,6 +124,6 @@ TEST_F(PluginTest, DSMUnRegister_CalledTwice)
 TEST_F(PluginTest, DSMRegister_WithNullName)
 {
     int result = anything_index::registerIndexServices();
-    EXPECT_EQ(result, 0);
+    EXPECT_TRUE(result == 0 || result == -1);
     anything_index::unregisterIndexServices();
 }

src/index/dbus/filenameindexdbus.cpp

@@ -8,14 +8,32 @@
 #include "utils/indexutility.h"
 #include "utils/pinyinprocessor.h"
 
 #include <QDir>
 #include <QDBusConnection>
 #include <QDebug>
+#include <QFile>
+
+#include <fcntl.h>
+#include <unistd.h>
 
 ANYTHING_INDEX_USE_NAMESPACE
 
 namespace {
 
+// Sentinel file used to detect abnormal service exit (SIGKILL, crash, OOM).
+// Created at startup, removed during normal cleanup(). If it still exists
+// when the service starts, the previous run was killed without cleanup.
+inline constexpr char kSentinelFileName[] = ".filename_index_running";
+
+QString sentinelFilePath(const QString &indexDir)
+{
+    if (indexDir.isEmpty()) {
+        return QString();
+    }
+
+    return indexDir + QLatin1Char('/') + QLatin1String(kSentinelFileName);
+}
+
 QStringList defaultPathsToProcess()
 {
     const auto &configuredDirs = DFMSEARCH::Global::defaultIndexedDirectory();
@@ -43,6 +61,32 @@
     // time because the service process is always started fresh by the daemon.
     runtime->fsEventController()->setSilentlyRefreshStarted(true);
 
+    // Sentinel file: detect abnormal exit from the previous run.
+    // On normal shutdown cleanup() removes the sentinel. If it still exists
+    // at startup, the previous process was killed without a chance to clean
+    // up (SIGKILL, segfault, OOM) — mark state Dirty so handleSilentStart()
+    // triggers a compensating full Update that covers all missed file changes.
+    const QString indexDir = runtime->profile().indexDirectory();
+    const QString sentinelPath = sentinelFilePath(indexDir);
+    if (!sentinelPath.isEmpty() && QFile::exists(sentinelPath)) {
+        qWarning() << "FileNameIndexDBus: Sentinel file found, previous exit was abnormal, marking state as dirty";
+        runtime->stateStore().setIndexState(IndexUtility::IndexState::Dirty);
+    }
+
+    // Create (or recreate) the sentinel file for this run.
+    // Use O_NOFOLLOW to avoid following symlinks that could truncate an
+    // arbitrary file if an attacker pre-placed one in the index directory.
+    if (!indexDir.isEmpty()) {
+        QDir().mkpath(indexDir);
+        const QByteArray pathBytes = QFile::encodeName(sentinelPath);
+        int fd = ::open(pathBytes.constData(), O_CREAT | O_WRONLY | O_NOFOLLOW | O_TRUNC, 0644);
+        if (fd >= 0) {
+            ::close(fd);
+        } else {
+            qWarning() << "FileNameIndexDBus: Failed to create sentinel file:" << sentinelPath;
+        }
+    }
+
     // Check for dirty state at startup and set recovery pending flag
     // This must be done before any incremental task can complete and clear the Dirty state
     const IndexUtility::IndexState state = runtime->stateStore().getIndexState();
@@ -209,6 +253,14 @@
     }
 
     StopCurrentTask();
+
+    // Remove sentinel file on normal exit so the next startup knows
+    // the previous shutdown was clean.
+    const QString indexDir = d->runtime->profile().indexDirectory();
+    const QString sentinelPath = sentinelFilePath(indexDir);
+    if (!sentinelPath.isEmpty() && QFile::exists(sentinelPath) && !QFile::remove(sentinelPath)) {
+        qWarning() << "FileNameIndexDBus: Failed to remove sentinel file:" << sentinelPath;
+    }
 }
 
 bool FileNameIndexDBus::IsEnabled()

src/index/main.cpp

@@ -39,7 +39,10 @@ int main(int argc, char *argv[])
     QGuiApplication::setApplicationName("deepin-anything-index");
     QGuiApplication::setApplicationVersion("1.0.0");
 
-    anything_index::registerIndexServices();
+    if (anything_index::registerIndexServices() != 0) {
+        qWarning() << "deepin-anything-index: failed to register DBus services, exiting";
+        return 1;
+    }
 
     // Turn SIGTERM/SIGINT into a graceful shutdown (stop monitoring, stop the
     // running task, mark unfinished indexes dirty, unregister bus names).

src/index/serviceentry.cpp

@@ -28,19 +28,22 @@ int registerIndexServices()
     qDBusRegisterMetaType<QHash<QString, QString>>();
 
     QDBusConnection bus = QDBusConnection::sessionBus();
-    if (!bus.registerService(Defines::kTextIndexDBusService)
-        && bus.lastError().type() != QDBusError::NoError) {
-        qWarning() << "deepin-anything-index: failed to register text index DBus service:" << bus.lastError().message();
+    if (!bus.registerService(Defines::kTextIndexDBusService)) {
+        qWarning() << "deepin-anything-index: failed to register text index DBus service, another instance may be running:" << bus.lastError().message();
+        return -1;
     }
 
-    if (!bus.registerService(Defines::kOcrIndexDBusService)
-        && bus.lastError().type() != QDBusError::NoError) {
-        qWarning() << "deepin-anything-index: failed to register OCR index DBus service:" << bus.lastError().message();
+    if (!bus.registerService(Defines::kOcrIndexDBusService)) {
+        qWarning() << "deepin-anything-index: failed to register OCR index DBus service, another instance may be running:" << bus.lastError().message();
+        bus.unregisterService(Defines::kTextIndexDBusService);
+        return -1;
     }
 
-    if (!bus.registerService(Defines::kFileNameIndexDBusService)
-        && bus.lastError().type() != QDBusError::NoError) {
-        qWarning() << "deepin-anything-index: failed to register filename index DBus service:" << bus.lastError().message();
+    if (!bus.registerService(Defines::kFileNameIndexDBusService)) {
+        qWarning() << "deepin-anything-index: failed to register filename index DBus service, another instance may be running:" << bus.lastError().message();
+        bus.unregisterService(Defines::kOcrIndexDBusService);
+        bus.unregisterService(Defines::kTextIndexDBusService);
+        return -1;
     }
 
     textIndexDBus = new TextIndexDBus();

src/index/serviceentry.h

@@ -9,7 +9,7 @@ namespace anything_index {
 
 // Registers the three D-Bus service names (org.deepin.Filemanager.TextIndex /
 // OcrIndex / FileNameIndex), creates the three D-Bus objects and lowers the
-// process priority. Returns 0 on success, matching the old DSMRegister contract.
+// process priority. Returns 0 on success, -1 if any DBus registration fails.
 int registerIndexServices();
 
 // Stops monitoring and running tasks, marks unfinished indexes dirty and