From b4f5c0f46c830b58e2268c10c22fc03d226f5209 Mon Sep 17 00:00:00 2001
From: Stanislav Angelovic <stanislav.angelovic@siemens.com>
Date: Thu, 22 Jul 2021 14:33:38 +0200
Subject: [PATCH] Catch sdbus-c++ exceptions flying from Proxy callbacks to
 libsystemd

---
 include/sdbus-c++/ConvenienceApiClasses.inl | 14 ++--------
 src/Object.cpp                              |  6 ++---
 src/Proxy.cpp                               | 29 ++++++++++++++++-----
 3 files changed, 27 insertions(+), 22 deletions(-)

diff --git a/include/sdbus-c++/ConvenienceApiClasses.inl b/include/sdbus-c++/ConvenienceApiClasses.inl
index 1d1f871..d144818 100644
--- a/include/sdbus-c++/ConvenienceApiClasses.inl
+++ b/include/sdbus-c++/ConvenienceApiClasses.inl
@@ -593,7 +593,7 @@ namespace sdbus {
                 {
                     reply >> args;
                 }
-                catch (const sdbus::Error& e)
+                catch (const Error& e)
                 {
                     // Catch message unpack exceptions and pass them to the callback
                     // in the expected manner to avoid propagating them up the call
@@ -641,17 +641,7 @@ namespace sdbus {
             tuple_of_function_input_arg_types_t<_Function> signalArgs;
 
             // Deserialize input arguments from the signal message into the tuple
-            try
-            {
-                signal >> signalArgs;
-            }
-            catch (const sdbus::Error& e)
-            {
-                // The convenience API callback cannot handle an incoming signal with
-                // an unexpected payload, so catch and ignore this exception to avoid
-                // propagating it up the call stack to the event loop.
-                return;
-            }
+            signal >> signalArgs;
 
             // Invoke callback with input arguments from the tuple.
             sdbus::apply(callback, signalArgs);
diff --git a/src/Object.cpp b/src/Object.cpp
index eb79a5c..94cf8d3 100644
--- a/src/Object.cpp
+++ b/src/Object.cpp
@@ -337,7 +337,7 @@ int Object::sdbus_method_callback(sd_bus_message *sdbusMessage, void *userData,
     {
         callback(message);
     }
-    catch (const sdbus::Error& e)
+    catch (const Error& e)
     {
         sd_bus_error_set(retError, e.getName().c_str(), e.getMessage().c_str());
     }
@@ -371,7 +371,7 @@ int Object::sdbus_property_get_callback( sd_bus */*bus*/
     {
         callback(reply);
     }
-    catch (const sdbus::Error& e)
+    catch (const Error& e)
     {
         sd_bus_error_set(retError, e.getName().c_str(), e.getMessage().c_str());
     }
@@ -406,7 +406,7 @@ int Object::sdbus_property_set_callback( sd_bus */*bus*/
     {
         callback(value);
     }
-    catch (const sdbus::Error& e)
+    catch (const Error& e)
     {
         sd_bus_error_set(retError, e.getName().c_str(), e.getMessage().c_str());
     }
diff --git a/src/Proxy.cpp b/src/Proxy.cpp
index 7796992..c6d0618 100644
--- a/src/Proxy.cpp
+++ b/src/Proxy.cpp
@@ -240,15 +240,22 @@ int Proxy::sdbus_async_reply_handler(sd_bus_message *sdbusMessage, void *userDat
         proxy.m_CurrentlyProcessedMessage.store(nullptr, std::memory_order_relaxed);
     };
 
-    const auto* error = sd_bus_message_get_error(sdbusMessage);
-    if (error == nullptr)
+    try
     {
-        asyncCallData->callback(message, nullptr);
+        const auto* error = sd_bus_message_get_error(sdbusMessage);
+        if (error == nullptr)
+        {
+            asyncCallData->callback(message, nullptr);
+        }
+        else
+        {
+            Error exception(error->name, error->message);
+            asyncCallData->callback(message, &exception);
+        }
     }
-    else
+    catch (const Error&)
     {
-        sdbus::Error exception(error->name, error->message);
-        asyncCallData->callback(message, &exception);
+        // Intentionally left blank -- sdbus-c++ exceptions shall not bubble up to the underlying C sd-bus library
     }
 
     return 1;
@@ -268,7 +275,15 @@ int Proxy::sdbus_signal_handler(sd_bus_message *sdbusMessage, void *userData, sd
         signalData->proxy.m_CurrentlyProcessedMessage.store(nullptr, std::memory_order_relaxed);
     };
 
-    signalData->callback(message);
+    try
+    {
+        signalData->callback(message);
+    }
+    catch (const Error&)
+    {
+        // Intentionally left blank -- sdbus-c++ exceptions shall not bubble up to the underlying C sd-bus library
+    }
+
     return 0;
 }