From 90392faa2b45f4bf70f300f7fd5871cfe645a1db Mon Sep 17 00:00:00 2001
From: chrchr-github <78114321+chrchr-github@users.noreply.github.com>
Date: Thu, 9 Jun 2022 18:25:17 +0200
Subject: [PATCH] Fix crash on nullptr deref (#4189)

---
 lib/token.cpp               |  2 +-
 test/testsymboldatabase.cpp | 16 +++++++++++-----
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/lib/token.cpp b/lib/token.cpp
index f61ae5c91..149bc1baa 100644
--- a/lib/token.cpp
+++ b/lib/token.cpp
@@ -2270,7 +2270,7 @@ std::pair<const Token*, const Token*> Token::typeDecl(const Token * tok)
         if (!function)
             return {};
         return { function->retDef, function->returnDefEnd() };
-    } else if (tok->previous()->function()) {
+    } else if (tok->previous() && tok->previous()->function()) {
         const Function *function = tok->previous()->function();
         return {function->retDef, function->returnDefEnd()};
     } else if (Token::simpleMatch(tok, "=")) {
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index 593ff3b3e..4030da2c1 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -4816,11 +4816,17 @@ private:
     }
 
     void symboldatabase92() { // daca crash
-        GET_SYMBOL_DB("template <size_t, typename...> struct a;\n"
-                      "template <size_t b, typename c, typename... d>\n"
-                      "struct a<b, c, d...> : a<1, d...> {};\n"
-                      "template <typename... e> struct f : a<0, e...> {};");
-        ASSERT_EQUALS("", errout.str());
+        {
+            GET_SYMBOL_DB("template <size_t, typename...> struct a;\n"
+                          "template <size_t b, typename c, typename... d>\n"
+                          "struct a<b, c, d...> : a<1, d...> {};\n"
+                          "template <typename... e> struct f : a<0, e...> {};");
+            ASSERT_EQUALS("", errout.str());
+        }
+        {
+            GET_SYMBOL_DB("b.f();");
+            ASSERT_EQUALS("", errout.str());
+        }
     }
 
     void symboldatabase93() { // alignas attribute