From a560a9e00d93b1bdd00f4971a72b0645c969944c Mon Sep 17 00:00:00 2001
From: Andrei Kortunov <andrei.kortunov@yandex.ru>
Date: Sat, 18 Aug 2018 16:12:01 +0400
Subject: [PATCH] Allow messageboxes arguments to have newline characters (bug
 #3836)

---
 CHANGELOG.md                    |  1 +
 components/compiler/scanner.cpp | 32 +++++++++++++++++++++++++++-----
 components/compiler/scanner.hpp |  6 ++++++
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c016ca82f..945d114b7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,7 @@
     Bug #3591: Angled hit distance too low
     Bug #3629: DB assassin attack never triggers creature spawning
     Bug #3788: GetPCInJail and GetPCTraveling do not work as in vanilla
+    Bug #3836: Script fails to compile when command argument contains "\n"
     Bug #3876: Landscape texture painting is misaligned
     Bug #3897: Have Goodbye give all choices the effects of Goodbye
     Bug #3911: [macOS] Typing in the "Content List name" dialog box produces double characters
diff --git a/components/compiler/scanner.cpp b/components/compiler/scanner.cpp
index bb0fb9374..257c3314e 100644
--- a/components/compiler/scanner.cpp
+++ b/components/compiler/scanner.cpp
@@ -306,10 +306,22 @@ namespace Compiler
         int i = 0;
 
         std::string lowerCase = Misc::StringUtils::lowerCase(name);
-
+        bool isKeyword = false;
         for (; sKeywords[i]; ++i)
             if (lowerCase==sKeywords[i])
+            {
+                isKeyword = true;
                 break;
+            }
+
+        // Russian localization and some mods use a quirk - add newline character directly
+        // to compiled bytecode via HEX-editor to implement multiline messageboxes.
+        // Of course, original editor will not compile such script.
+        // Allow messageboxes to bybass the "incomplete string or name" error.
+        if (lowerCase == "messagebox")
+            enableIgnoreNewlines();
+        else if (isKeyword)
+            mIgnoreNewline = false;
 
         if (sKeywords[i])
         {
@@ -357,9 +369,14 @@ namespace Compiler
 //                }
                 else if (c=='\n')
                 {
-                    error = true;
-                    mErrorHandler.error ("incomplete string or name", mLoc);
-                    break;
+                    if (mIgnoreNewline)
+                        mErrorHandler.warning ("string contains newline character, make sure that it is intended", mLoc);
+                    else
+                    {
+                        error = true;
+                        mErrorHandler.error ("incomplete string or name", mLoc);
+                        break;
+                    }
                 }
             }
             else if (!(c=='"' && name.empty()))
@@ -578,7 +595,7 @@ namespace Compiler
         const Extensions *extensions)
     : mErrorHandler (errorHandler), mStream (inputStream), mExtensions (extensions),
       mPutback (Putback_None), mPutbackCode(0), mPutbackInteger(0), mPutbackFloat(0),
-      mStrictKeywords (false), mTolerantNames (false)
+      mStrictKeywords (false), mTolerantNames (false), mIgnoreNewline(false)
     {
     }
 
@@ -631,6 +648,11 @@ namespace Compiler
             mExtensions->listKeywords (keywords);
     }
 
+    void Scanner::enableIgnoreNewlines()
+    {
+        mIgnoreNewline = true;
+    }
+
     void Scanner::enableStrictKeywords()
     {
         mStrictKeywords = true;
diff --git a/components/compiler/scanner.hpp b/components/compiler/scanner.hpp
index 49fbaa96a..a431cabb2 100644
--- a/components/compiler/scanner.hpp
+++ b/components/compiler/scanner.hpp
@@ -39,6 +39,7 @@ namespace Compiler
             TokenLoc mPutbackLoc;
             bool mStrictKeywords;
             bool mTolerantNames;
+            bool mIgnoreNewline;
 
         public:
 
@@ -126,6 +127,11 @@ namespace Compiler
             void listKeywords (std::vector<std::string>& keywords);
             ///< Append all known keywords to \a keywords.
 
+            /// Treat newline character as a part of script command.
+            ///
+            /// \attention This mode lasts only until the next keyword is reached.
+            void enableIgnoreNewlines();
+
             /// Do not accept keywords in quotation marks anymore.
             ///
             /// \attention This mode lasts only until the next newline is reached.