From 02775c490bbd3a601436815807492664574a7517 Mon Sep 17 00:00:00 2001
From: Evil Eye <malusluminis@hotmail.com>
Date: Thu, 28 Dec 2023 21:49:25 +0100
Subject: [PATCH] Discard additional tokens in non-expression contexts

---
 .../mwscript/test_scripts.cpp                 | 26 ++++++++++++++++++-
 components/compiler/lineparser.cpp            | 13 +++++-----
 components/compiler/skipparser.cpp            | 20 ++++++++++++--
 components/compiler/skipparser.hpp            |  6 ++++-
 4 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/apps/openmw_test_suite/mwscript/test_scripts.cpp b/apps/openmw_test_suite/mwscript/test_scripts.cpp
index b623084fb9..dbed262235 100644
--- a/apps/openmw_test_suite/mwscript/test_scripts.cpp
+++ b/apps/openmw_test_suite/mwscript/test_scripts.cpp
@@ -19,7 +19,16 @@ namespace
             mErrorHandler.reset();
             std::istringstream input(scriptBody);
             Compiler::Scanner scanner(mErrorHandler, input, mCompilerContext.getExtensions());
-            scanner.scan(mParser);
+            try
+            {
+                scanner.scan(mParser);
+            }
+            catch (...)
+            {
+                if (!shouldFail)
+                    logErrors();
+                throw;
+            }
             if (mErrorHandler.isGood())
                 return CompiledScript(mParser.getProgram(), mParser.getLocals());
             else if (!shouldFail)
@@ -385,6 +394,12 @@ if (player->GameHour == 10)
 set player->GameHour to 20
 endif
 
+End)mwscript";
+
+    const std::string sIssue4996 = R"mwscript(---Begin issue4996
+
+player-> SetPos, Z, myZ + 50
+
 End)mwscript";
 
     const std::string sIssue5087 = R"mwscript(Begin Begin
@@ -457,6 +472,9 @@ set a to 1
 
 -+'\/.,><$@---!=\/?--------(){}------ show a
 
+( GetDisabled == 1 )
+GetDisabled == 1
+
 End)mwscript";
 
     TEST_F(MWScriptTest, mwscript_test_invalid)
@@ -810,6 +828,12 @@ End)mwscript";
         EXPECT_FALSE(!compile(sIssue4888));
     }
 
+    TEST_F(MWScriptTest, mwscript_test_4996)
+    {
+        registerExtensions();
+        EXPECT_FALSE(!compile(sIssue4996));
+    }
+
     TEST_F(MWScriptTest, mwscript_test_5087)
     {
         registerExtensions();
diff --git a/components/compiler/lineparser.cpp b/components/compiler/lineparser.cpp
index 460dcfb2f9..90bdac1610 100644
--- a/components/compiler/lineparser.cpp
+++ b/components/compiler/lineparser.cpp
@@ -271,18 +271,14 @@ namespace Compiler
                     mCode.insert(mCode.end(), code.begin(), code.end());
                     extensions->generateInstructionCode(keyword, mCode, mLiterals, mExplicit, optionals);
 
+                    SkipParser skip(getErrorHandler(), getContext(), true);
+                    scanner.scan(skip);
+
                     mState = EndState;
                     return true;
                 }
-            }
 
-            if (const Extensions* extensions = getContext().getExtensions())
-            {
                 char returnType;
-                std::string argumentType;
-
-                bool hasExplicit = mState == ExplicitState;
-
                 if (extensions->isFunction(keyword, returnType, argumentType, hasExplicit))
                 {
                     if (!hasExplicit && mState == ExplicitState)
@@ -302,6 +298,9 @@ namespace Compiler
                         int optionals = mExprParser.parseArguments(argumentType, scanner, code, keyword);
                         mCode.insert(mCode.end(), code.begin(), code.end());
                         extensions->generateFunctionCode(keyword, mCode, mLiterals, mExplicit, optionals);
+
+                        SkipParser skip(getErrorHandler(), getContext(), true);
+                        scanner.scan(skip);
                     }
                     mState = EndState;
                     return true;
diff --git a/components/compiler/skipparser.cpp b/components/compiler/skipparser.cpp
index 0036e93dda..39d834c8ca 100644
--- a/components/compiler/skipparser.cpp
+++ b/components/compiler/skipparser.cpp
@@ -1,39 +1,55 @@
 #include "skipparser.hpp"
 
+#include "errorhandler.hpp"
 #include "scanner.hpp"
 
 namespace Compiler
 {
-    SkipParser::SkipParser(ErrorHandler& errorHandler, const Context& context)
+    SkipParser::SkipParser(ErrorHandler& errorHandler, const Context& context, bool reportStrayArguments)
         : Parser(errorHandler, context)
+        , mReportStrayArguments(reportStrayArguments)
     {
     }
 
+    void SkipParser::reportStrayArgument(const TokenLoc& loc)
+    {
+        if (mReportStrayArguments)
+            getErrorHandler().warning("Extra argument", loc);
+    }
+
     bool SkipParser::parseInt(int value, const TokenLoc& loc, Scanner& scanner)
     {
+        reportStrayArgument(loc);
         return true;
     }
 
     bool SkipParser::parseFloat(float value, const TokenLoc& loc, Scanner& scanner)
     {
+        reportStrayArgument(loc);
         return true;
     }
 
     bool SkipParser::parseName(const std::string& name, const TokenLoc& loc, Scanner& scanner)
     {
+        reportStrayArgument(loc);
         return true;
     }
 
     bool SkipParser::parseKeyword(int keyword, const TokenLoc& loc, Scanner& scanner)
     {
+        reportStrayArgument(loc);
         return true;
     }
 
     bool SkipParser::parseSpecial(int code, const TokenLoc& loc, Scanner& scanner)
     {
         if (code == Scanner::S_newline)
+        {
+            if (mReportStrayArguments)
+                scanner.putbackSpecial(code, loc);
             return false;
-
+        }
+        reportStrayArgument(loc);
         return true;
     }
 }
diff --git a/components/compiler/skipparser.hpp b/components/compiler/skipparser.hpp
index fdc5effc13..304ed40330 100644
--- a/components/compiler/skipparser.hpp
+++ b/components/compiler/skipparser.hpp
@@ -11,8 +11,12 @@ namespace Compiler
 
     class SkipParser : public Parser
     {
+        bool mReportStrayArguments;
+
+        void reportStrayArgument(const TokenLoc& loc);
+
     public:
-        SkipParser(ErrorHandler& errorHandler, const Context& context);
+        SkipParser(ErrorHandler& errorHandler, const Context& context, bool reportStrayArguments = false);
 
         bool parseInt(int value, const TokenLoc& loc, Scanner& scanner) override;
         ///< Handle an int token.