From b97387db667498aca6cb284ca40ddf1346cba25b Mon Sep 17 00:00:00 2001
From: abhijit-sawant <abhijit.abhi1980@gmail.com>
Date: Mon, 18 Jan 2021 02:11:37 -0500
Subject: [PATCH] Made missing comparison in loop check more generic (#3048)

---
 lib/checkstl.cpp | 13 ++++---------
 test/teststl.cpp |  5 ++++-
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/lib/checkstl.cpp b/lib/checkstl.cpp
index ac51a00cd..f4bc4f8f2 100644
--- a/lib/checkstl.cpp
+++ b/lib/checkstl.cpp
@@ -1732,8 +1732,6 @@ void CheckStl::missingComparison()
             }
 
             const Token *incrementToken = nullptr;
-            bool bComparedInAdvance = false;
-
             // Parse loop..
             for (const Token *tok3 = scope.bodyStart; tok3 != scope.bodyEnd; tok3 = tok3->next()) {
                 if (tok3->varId() == iteratorId) {
@@ -1742,16 +1740,13 @@ void CheckStl::missingComparison()
                         tok3 = tok3->linkAt(6);
                         if (!tok3)
                             break;
-                    } else if (Token::simpleMatch(tok3->astParent(), "++")) {
-                        if (!bComparedInAdvance)
+                    } else if (Token::simpleMatch(tok3->astParent(), "++"))
                             incrementToken = tok3;
-                        else
-                            bComparedInAdvance = false;
-                    } else if (Token::simpleMatch(tok3->astParent(), "+")) {
-                        if (Token::simpleMatch(tok3->astSibling(), "1")) {
+                    else if (Token::simpleMatch(tok3->astParent(), "+")) {
+                        if (Token::Match(tok3->astSibling(), "%num%")) {
                             const Token* tokenGrandParent = tok3->astParent()->astParent();
                             if (Token::Match(tokenGrandParent, "==|!="))
-                                bComparedInAdvance = true;
+                                break;
                         }
                     } else if (Token::Match(tok3->astParent(), "==|!="))
                         incrementToken = nullptr;
diff --git a/test/teststl.cpp b/test/teststl.cpp
index 68076334e..a440fa44e 100644
--- a/test/teststl.cpp
+++ b/test/teststl.cpp
@@ -3004,8 +3004,11 @@ private:
 
         check("void f(const std::vector<std::string> &v) {\n"
               "    for(std::vector<std::string>::const_iterator it = v.begin(); it != v.end(); ++it) {\n"
-              "        if(it+1 != v.end())\n"
+              "        if(it+2 != v.end())\n"
+              "        {\n"
               "            ++it;\n"
+              "            ++it;\n"
+              "        }\n"
               "    }\n"
               "}");
         ASSERT_EQUALS("", errout.str());