Do not crash when there is no DRY sampler (#578)

Co-authored-by: Iwan Kawrakow <[email protected]>

Author: ikawrakow

common/sampling.cpp

@@ -55,7 +55,7 @@ struct llama_sampling_context * llama_sampling_init(const struct llama_vocab* vo
                     c_breakers.push_back(str.c_str());
                 }
                 result->smpl=llama_sampler_init_dry(vocab, params.dry_multiplier, params.dry_base, params.dry_allowed_length, params.dry_penalty_last_n, c_breakers.data(), c_breakers.size());
-                
+
                 break;
             }
             default:
@@ -502,5 +502,7 @@ void llama_sampling_accept(
     if (ctx_sampling->grammar != NULL && apply_grammar) {
         llama_grammar_accept_token(ctx_sampling->grammar, ctx_main, id);
     }
-    llama_sampler_dry_accept(ctx_sampling->smpl, id);
+    if (ctx_sampling->smpl) {
+        llama_sampler_dry_accept(ctx_sampling->smpl, id);
+    }
 }

src/llama.cpp

@@ -23401,6 +23401,9 @@ struct llama_sampler_dry* llama_sampler_dry_clone(struct llama_sampler_dry* smpl
 }
 
 void llama_sampler_dry_accept(struct llama_sampler_dry* smpl, llama_token token) {
+    if (!smpl) {
+        return;
+    }
     if (smpl->dry_multiplier == 0.0f || smpl->dry_base < 1.0f || smpl->dry_penalty_last_n == 0) {
         return;
     }