From 13556104c0cad95fa1a2cde692964242348aaad8 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Mon, 29 Sep 2025 09:26:10 +0200
Subject: [PATCH 1/2] Update test.cpp

---
 test.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test.cpp b/test.cpp
index b9869b5b..f42b2189 100644
--- a/test.cpp
+++ b/test.cpp
@@ -3259,6 +3259,12 @@ static void fuzz_crash()
                             "foo(f##oo(intp))\n";
         (void)preprocess(code, simplecpp::DUI()); // do not crash
     }
+    { // #546
+        const char code[] = "#if __has_include<\n";
+        simplecpp::OutputList outputList;
+        ASSERT_EQUALS("", preprocess(code, &outputList)); // do not crash
+        ASSERT_EQUALS("file0,1,syntax_error,failed to evaluate #if condition\n", toString(outputList));
+    }
 }
 
 // memory leaks detected by LSAN/valgrind

From f47939af8ccca231afa561067844d3d88a4c8685 Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Mon, 29 Sep 2025 09:27:30 +0200
Subject: [PATCH 2/2] Update simplecpp.cpp

---
 simplecpp.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/simplecpp.cpp b/simplecpp.cpp
index 320836be..c5760145 100644
--- a/simplecpp.cpp
+++ b/simplecpp.cpp
@@ -3602,9 +3602,11 @@ void simplecpp::preprocess(simplecpp::TokenList &output, const simplecpp::TokenL
                                     header = tok->str().substr(1U, tok->str().size() - 2U);
                                     closingAngularBracket = true;
                                 }
-                                std::ifstream f;
-                                const std::string header2 = openHeader(f,dui,sourcefile,header,systemheader);
-                                expr.push_back(new Token(header2.empty() ? "0" : "1", tok->location));
+                                if (tok) {
+                                    std::ifstream f;
+                                    const std::string header2 = openHeader(f,dui,sourcefile,header,systemheader);
+                                    expr.push_back(new Token(header2.empty() ? "0" : "1", tok->location));
+                                }
                             }
                             if (par)
                                 tok = tok ? tok->next : nullptr;