From 780481e82a40d8665afd832c079bdb5d12753618 Mon Sep 17 00:00:00 2001
From: Ahti Legonkov <ahti.legonkov@gmail.com>
Date: Fri, 23 Mar 2012 01:45:47 +0200
Subject: [PATCH] Fixed ticket #3675.

---
 lib/preprocessor.cpp      |  2 +-
 test/testpreprocessor.cpp | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/lib/preprocessor.cpp b/lib/preprocessor.cpp
index 3326f6df5..e747ab837 100644
--- a/lib/preprocessor.cpp
+++ b/lib/preprocessor.cpp
@@ -889,7 +889,7 @@ static void simplifyVarMap(std::map<std::string, std::string> &variables)
         // TODO: 2. handle function-macros too.
 
         std::map<std::string, std::string>::iterator it = variables.find(varValue);
-        while (it != variables.end() && it != i) {
+        while (it != variables.end() && it->first != it->second && it != i) {
             varValue = it->second;
             it = variables.find(varValue);
         }
diff --git a/test/testpreprocessor.cpp b/test/testpreprocessor.cpp
index 99761bbc5..aa8fef626 100644
--- a/test/testpreprocessor.cpp
+++ b/test/testpreprocessor.cpp
@@ -129,6 +129,7 @@ private:
         TEST_CASE(if_or_2);
 
         TEST_CASE(if_macro_eq_macro); // #3536
+        TEST_CASE(ticket_3675);
 
         TEST_CASE(multiline1);
         TEST_CASE(multiline2);
@@ -1521,6 +1522,23 @@ private:
         ASSERT_EQUALS("\n\n\n\nWilma\n\n\n\n", actual[""]);
     }
 
+    void ticket_3675() {
+        const std::string code("#ifdef YYSTACKSIZE\n"
+                               "#define YYMAXDEPTH YYSTACKSIZE\n"
+                               "#else\n"
+                               "#define YYSTACKSIZE YYMAXDEPTH\n"
+                               "#endif\n"
+                               "#if YYDEBUG\n"
+                               "#endif\n");
+        Settings settings;
+        Preprocessor preprocessor(&settings, this);
+        std::istringstream istr(code);
+        std::map<std::string, std::string> actual;
+        preprocessor.preprocess(istr, actual, "file.c");
+
+        // There's nothing to assert. It just needs to not hang.
+    }
+
     void multiline1() {
         const char filedata[] = "#define str \"abc\"     \\\n"
                                 "            \"def\"       \n"