nicer error handling in the tonemapper when given the -t parameter

src/utils/tonemap.cpp

@@ -283,6 +283,7 @@ public:
 
 		if (runParallel) {
 			ref<Logger> logger = Thread::getThread()->getLogger();
+			std::vector<std::string> messages;
 
 			#if defined(MTS_OPENMP)
 				#pragma omp parallel for schedule(static)
@@ -293,7 +294,7 @@ public:
 					thread = Thread::registerUnmanagedThread("omp");
 					thread->setLogger(logger);
 				}
-
+				try {
 					fs::path inputFile = fileResolver->resolve(argv[i]);
 					Log(EInfo, "Loading image \"%s\" ..", inputFile.string().c_str());
 					ref<FileStream> is = new FileStream(inputFile, FileStream::EReadOnly);
@@ -349,6 +350,15 @@ public:
 
 					ref<FileStream> os = new FileStream(outputFile, FileStream::ETruncReadWrite);
 					output->write(format, os);
+				} catch (const std::exception &e) {
+					#pragma omp critical
+					messages.push_back(e.what());
+				}
+			}
+			if (!messages.empty()) {
+				Log(EWarn, "The tonemapping worker threads encountered several issues:");
+				for (size_t i=0; i<messages.size(); ++i)
+					Log(EWarn, "Exception %i: %s", (int) i, messages[i].c_str());
 			}
 		} else {
 			ref<Bitmap> bloomFilter;