--- a/OrthancServer/Plugins/Engine/OrthancPlugins.cpp	Wed May 21 21:29:52 2025 +0200
+++ b/OrthancServer/Plugins/Engine/OrthancPlugins.cpp	Wed May 21 21:31:14 2025 +0200
@@ -4737,11 +4737,11 @@
     if (lock.GetContext().GetIndex().GetKeyValue(value, parameters.storeId, parameters.key))
     {
       CopyToMemoryBuffer(*parameters.target, value.size() > 0 ? value.c_str() : NULL, value.size());
-      *parameters.isExisting = true;
+      *parameters.found = true;
     }
     else
     {
-      *parameters.isExisting = false;
+      *parameters.found = false;
     }
   }
 
@@ -4769,11 +4769,11 @@
     if (lock.GetContext().GetIndex().DequeueValue(value, parameters.queueId, Plugins::Convert(parameters.origin)))
     {
       CopyToMemoryBuffer(*parameters.target, value.size() > 0 ? value.c_str() : NULL, value.size());
-      *parameters.isExisting = true;
+      *parameters.found = true;
     }
     else
     {
-      *parameters.isExisting = false;
+      *parameters.found = false;
     }
   }
 

--- a/OrthancServer/Plugins/Include/orthanc/OrthancCPlugin.h	Wed May 21 21:29:52 2025 +0200
+++ b/OrthancServer/Plugins/Include/orthanc/OrthancCPlugin.h	Wed May 21 21:31:14 2025 +0200
@@ -9970,7 +9970,7 @@
 
   typedef struct
   {
-    uint8_t*                      isExisting;
+    uint8_t*                      found;
     OrthancPluginMemoryBuffer*    target;
     const char*                   storeId;
     const char*                   key;
@@ -9980,7 +9980,7 @@
    * @brief Get the value associated to this key in the key-value store.
    *
    * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
-   * @param isExisting Pointer to a Boolean that is set to "true" iff. the key exists in the store
+   * @param found Pointer to a Boolean that is set to "true" iff. the key exists in the store
    * @param target Memory buffer where to store the retrieved value
    * @param storeId A unique identifier identifying both the plugin and the store
    * @param key The key of the value to retrieve from the store (note: storeId + key must be unique)
@@ -9988,13 +9988,13 @@
    **/
   ORTHANC_PLUGIN_INLINE OrthancPluginErrorCode OrthancPluginGetKeyValue(
     OrthancPluginContext*         context,
-    uint8_t*                      isExisting,
+    uint8_t*                      found,
     OrthancPluginMemoryBuffer*    target, /* out */
     const char*                   storeId, /* in */
     const char*                   key /* in */)
   {
     _OrthancPluginGetKeyValue params;
-    params.isExisting = isExisting;
+    params.found = found;
     params.target = target;
     params.storeId = storeId;
     params.key = key;
@@ -10168,7 +10168,7 @@
 
   typedef struct
   {
-    uint8_t*                      isExisting;
+    uint8_t*                      found;
     OrthancPluginMemoryBuffer*    target;
     const char*                   queueId;
     OrthancPluginQueueOrigin      origin;
@@ -10178,7 +10178,7 @@
    * @brief Dequeue a value from a queue.
    *
    * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
-   * @param isExisting Pointer to a Boolean that is set to "true" iff. a value has been dequeued
+   * @param found Pointer to a Boolean that is set to "true" iff. a value has been dequeued
    * @param target Memory buffer where to store the value that has been retrieved from the queue
    * @param queueId A unique identifier identifying both the plugin and the queue
    * @param origin The queue position where the value is removed (back for LIFO, front for FIFO)
@@ -10186,13 +10186,13 @@
    **/
   ORTHANC_PLUGIN_INLINE OrthancPluginErrorCode OrthancPluginDequeueValue(
     OrthancPluginContext*         context,
-    uint8_t*                      isExisting,  /* out */
-    OrthancPluginMemoryBuffer*    target,      /* out */
-    const char*                   queueId,     /* in */
-    OrthancPluginQueueOrigin      origin       /* in */)
+    uint8_t*                      found,    /* out */
+    OrthancPluginMemoryBuffer*    target,   /* out */
+    const char*                   queueId,  /* in */
+    OrthancPluginQueueOrigin      origin    /* in */)
   {
     _OrthancPluginDequeueValue params;
-    params.isExisting = isExisting;
+    params.found = found;
     params.target = target;
     params.queueId = queueId;
     params.origin = origin;

--- a/OrthancServer/Plugins/Samples/Common/OrthancPluginCppWrapper.cpp	Wed May 21 21:29:52 2025 +0200
+++ b/OrthancServer/Plugins/Samples/Common/OrthancPluginCppWrapper.cpp	Wed May 21 21:31:14 2025 +0200
@@ -4437,16 +4437,16 @@
   bool KeyValueStore::GetValue(std::string& value,
                                const std::string& key)
   {
-    uint8_t isExisting = false;
+    uint8_t found = false;
     OrthancPlugins::MemoryBuffer valueBuffer;
-    OrthancPluginErrorCode code = OrthancPluginGetKeyValue(OrthancPlugins::GetGlobalContext(), &isExisting,
+    OrthancPluginErrorCode code = OrthancPluginGetKeyValue(OrthancPlugins::GetGlobalContext(), &found,
                                                            *valueBuffer, storeId_.c_str(), key.c_str());
 
     if (code != OrthancPluginErrorCode_Success)
     {
       ORTHANC_PLUGINS_THROW_PLUGIN_ERROR_CODE(code);
     }
-    else if (isExisting)
+    else if (found)
     {
       valueBuffer.ToString(value);
       return true;
@@ -4499,17 +4499,17 @@
   bool Queue::PopInternal(std::string& value,
                           OrthancPluginQueueOrigin origin)
   {
-    uint8_t isExisting = false;
+    uint8_t found = false;
     OrthancPlugins::MemoryBuffer valueBuffer;
 
-    OrthancPluginErrorCode code = OrthancPluginDequeueValue(OrthancPlugins::GetGlobalContext(), &isExisting,
+    OrthancPluginErrorCode code = OrthancPluginDequeueValue(OrthancPlugins::GetGlobalContext(), &found,
                                                             *valueBuffer, queueId_.c_str(), origin);
 
     if (code != OrthancPluginErrorCode_Success)
     {
       ORTHANC_PLUGINS_THROW_PLUGIN_ERROR_CODE(code);
     }
-    else if (isExisting)
+    else if (found)
     {
       valueBuffer.ToString(value);
       return true;

--- a/OrthancServer/Sources/Database/StatelessDatabaseOperations.cpp	Wed May 21 21:29:52 2025 +0200
+++ b/OrthancServer/Sources/Database/StatelessDatabaseOperations.cpp	Wed May 21 21:31:14 2025 +0200
@@ -3644,6 +3644,13 @@
       throw OrthancException(ErrorCode_DatabasePlugin);
     }
 
+    if (limit_ != 0 &&
+        keys_.size() > limit_)
+    {
+      // The database plugin has returned too many key-value pairs
+      throw OrthancException(ErrorCode_DatabasePlugin);
+    }
+
     if (keys_.empty() &&
         values_.empty())
     {