fix out_of_range error to keep the chat loop running

Author: ahmedshakill

examples/llava/mtmd-cli.cpp

@@ -308,7 +308,7 @@ int main(int argc, char ** argv) {
             }
             g_is_generating = true;
             if (line.find("/image") == 0) {
-                std::string image = line.substr(7);
+                std::string image = (line.size()>=7) ? line.substr(7) : "";
                 images_fname.push_back(string_strip(image));
                 content += "<__image__>";
                 continue;

examples/llava/mtmd.cpp

@@ -590,7 +590,7 @@ int32_t mtmd_helper_eval(mtmd_context * ctx,
             }
 
         } else if (chunk.type == MTMD_INPUT_CHUNK_TYPE_IMAGE) {
-            GGML_ASSERT(!is_last && "logits for last image chunk is not yet support");
+            GGML_ASSERT(!is_last && "logits for last image chunk is not yet supported");
             GGML_ASSERT(chunk.tokens_image != nullptr);
             int64_t t0 = ggml_time_ms();
             if (ctx->print_timings) {