From 242780e451ca4db5f4956413bade605dfc7fb5c7 Mon Sep 17 00:00:00 2001
From: Christian Krause <me@ckrause.org>
Date: Tue, 29 Oct 2024 21:51:42 +0100
Subject: [PATCH] handle errors in folded programs

---
 src/cmd/commands.cpp     | 19 ++++++++++++++++---
 src/eval/interpreter.cpp |  6 ++++--
 src/eval/interpreter.hpp |  2 ++
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/cmd/commands.cpp b/src/cmd/commands.cpp
index 8e388618..4e4fa531 100644
--- a/src/cmd/commands.cpp
+++ b/src/cmd/commands.cpp
@@ -357,10 +357,23 @@ void Commands::autoFold() {
       auto terms = seq.getTerms(OeisSequence::DEFAULT_SEQ_LENGTH);
       auto result = evaluator.check(main, terms, -1, main_id);
       if (result.first == status_t::ERROR) {
-        Log::get().error("Error in folded program", true);
+        Sequence tmp;
+        std::string error_msg;
+        try {
+          evaluator.eval(main, tmp, terms.size(), true);
+        } catch (std::exception& e) {
+          error_msg = e.what();
+        }
+        if (error_msg.find(Interpreter::ERROR_SEQ_USING_NEGATIVE_ARG) !=
+            std::string::npos) {
+          Log::get().warn("Ignoring invalid folded program");
+        } else {
+          Log::get().error("Unknown error in folded program", true);
+        }
+      } else {
+        auto path = ProgramUtil::getProgramPath(main_id);
+        manager.dumpProgram(main_id, main, path, submitted_by);
       }
-      auto path = ProgramUtil::getProgramPath(main_id);
-      manager.dumpProgram(main_id, main, path, submitted_by);
     }
     if (log_scheduler.isTargetReached()) {
       log_scheduler.reset();
diff --git a/src/eval/interpreter.cpp b/src/eval/interpreter.cpp
index be2722ae..fa28ab7f 100644
--- a/src/eval/interpreter.cpp
+++ b/src/eval/interpreter.cpp
@@ -21,6 +21,9 @@
 #include <unistd.h>
 #endif
 
+const std::string Interpreter::ERROR_SEQ_USING_NEGATIVE_ARG =
+    "seq using negative argument";
+
 using MemStack = std::stack<Memory>;
 using IntStack = std::stack<int64_t>;
 using NumStack = std::stack<Number>;
@@ -395,8 +398,7 @@ std::string getProgramPath(int64_t id) {
 
 std::pair<Number, size_t> Interpreter::callSeq(int64_t id, const Number& arg) {
   if (arg < 0) {
-    throw std::runtime_error("seq using negative argument: " +
-                             std::to_string(id));
+    throw std::runtime_error(ERROR_SEQ_USING_NEGATIVE_ARG);
   }
 
   // check if already cached
diff --git a/src/eval/interpreter.hpp b/src/eval/interpreter.hpp
index a47d25b0..234692bb 100644
--- a/src/eval/interpreter.hpp
+++ b/src/eval/interpreter.hpp
@@ -9,6 +9,8 @@
 
 class Interpreter {
  public:
+  static const std::string ERROR_SEQ_USING_NEGATIVE_ARG;
+
   explicit Interpreter(const Settings &settings);
 
   static Number calc(const Operation::Type type, const Number &target,