From f8710cb98458c48a483d87d2d5d7d135948bc8f9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Fri, 18 Oct 2013 06:47:55 +0200
Subject: [PATCH] Fixed #5102 (Crash if -D is used when scanning simple
 preprocessor code.)

---
 lib/preprocessor.cpp      |  5 +++++
 test/testpreprocessor.cpp | 16 ++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 5e47bf5c1..4d6d37081 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -2052,6 +2052,11 @@ std::string Preprocessor::handleIncludes(const std::string &code, const std::str
             }
         }
 
+        if (elseIsTrueStack.empty()) {
+			writeError(filePath, linenr, _errorLogger, "syntaxError", "Syntax error in preprocessor code");
+            return "";
+        }
+
         std::stack<bool>::reference elseIsTrue = elseIsTrueStack.top();
 
         if (line == "#pragma once") {
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index 2641f609e..f111228c7 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -93,6 +93,7 @@ private:
         TEST_CASE(test7d);
         TEST_CASE(test7e);
         TEST_CASE(test8);  // #if A==1  => cfg: A=1
+        TEST_CASE(test9);  // Don't crash for invalid code
 
         // #error => don't extract any code
         TEST_CASE(error1);
@@ -778,6 +779,21 @@ private:
         ASSERT_EQUALS("\n1\n\n", actual["A=1"]);
     }
 
+    void test9() {
+        const char filedata[] = "#if\n"
+                                "#else\n"
+                                "#endif\n";
+
+        // Preprocess => actual result..
+        std::istringstream istr(filedata);
+        std::map<std::string, std::string> actual;
+        Settings settings;
+        settings._maxConfigs = 1;
+        settings.userDefines = "X";
+        Preprocessor preprocessor(&settings, this);
+        preprocessor.preprocess(istr, actual, "file.c"); // <- don't crash
+    }
+
     void error1() {
         const char filedata[] = "#ifdef A\n"
                                 ";\n"