Harden against the missing message in generate_reproducer.

Author: vsapsai

Sources/SWBCSupport/CLibclang.cpp

@@ -2183,7 +2183,7 @@ extern "C" {
             argc, const_cast<const char**>(argv), workingDirectory,
             /*ReproducerLocation=*/NULL, /*UseUniqueReproducerName=*/true, &messageString);
         if (message) {
-            *message = strdup(lib->fns.clang_getCString(messageString));
+            *message = strdup_safe(lib->fns.clang_getCString(messageString));
         }
         lib->fns.clang_disposeString(messageString);
         return result == LibclangFunctions::CXError_Success;

Sources/SWBCore/LibclangVendored/Libclang.swift

@@ -285,7 +285,7 @@ public final class DependencyScanner {
         let success = libclang_scanner_generate_reproducer(scanner, CInt(args.cArray.count - 1), args.cArray, workingDirectory, &messageUnsafe);
         let message = String(cString: messageUnsafe)
         guard success else {
-            throw Error.dependencyScanErrorString(message)
+            throw message.isEmpty ? Error.dependencyScanUnknownError : Error.dependencyScanErrorString(message)
         }
         return message
     }