From 3773d0e875c36347a93f4c9538dc7e9027cce9c2 Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Tue, 7 Apr 2020 00:15:15 -0500
Subject: [PATCH] Find more redundant conditions (#2597)

---
 lib/checkcondition.cpp | 27 +++++++++++++++++++++++++++
 test/testcondition.cpp | 10 ++++++++++
 2 files changed, 37 insertions(+)

diff --git a/lib/checkcondition.cpp b/lib/checkcondition.cpp
index cde8df023..111ce80dc 100644
--- a/lib/checkcondition.cpp
+++ b/lib/checkcondition.cpp
@@ -1054,6 +1054,8 @@ void CheckCondition::checkIncorrectLogicOperator()
 
             // 'A && (!A || B)' is equivalent to 'A && B'
             // 'A || (!A && B)' is equivalent to 'A || B'
+            // 'A && (A || B)' is equivalent to 'A'
+            // 'A || (A && B)' is equivalent to 'A'
             if (printStyle &&
                 ((tok->str() == "||" && tok->astOperand2()->str() == "&&") ||
                  (tok->str() == "&&" && tok->astOperand2()->str() == "||"))) {
@@ -1089,6 +1091,31 @@ void CheckCondition::checkIncorrectLogicOperator()
                                             "The condition '" + cond1VerboseMsg + "' is equivalent to '" + cond2VerboseMsg + "'.";
                     redundantConditionError(tok, msg, false);
                     continue;
+                } else if (isSameExpression(mTokenizer->isCPP(), false, tok->astOperand1(), tok2, mSettings->library, true, true)) {
+                    std::string expr1(tok->astOperand1()->expressionString());
+                    std::string expr2(tok->astOperand2()->astOperand1()->expressionString());
+                    std::string expr3(tok->astOperand2()->astOperand2()->expressionString());
+                    // make copy for later because the original string might get overwritten
+                    const std::string expr1VerboseMsg = expr1;
+                    const std::string expr2VerboseMsg = expr2;
+                    const std::string expr3VerboseMsg = expr3;
+
+                    if (expr1.length() + expr2.length() + expr3.length() > 50U) {
+                        expr1 = "A";
+                        expr2 = "A";
+                        expr3 = "B";
+                    }
+
+                    const std::string cond1 = expr1 + " " + tok->str() + " (" + expr2 + " " + tok->astOperand2()->str() + " " + expr3 + ")";
+                    const std::string cond2 = expr1;
+
+                    const std::string cond1VerboseMsg = expr1VerboseMsg + " " + tok->str() + " " + expr2VerboseMsg + " " + tok->astOperand2()->str() + " " + expr3VerboseMsg;
+                    const std::string cond2VerboseMsg = expr1VerboseMsg;
+                    // for the --verbose message, transform the actual condition and print it
+                    const std::string msg = tok2->expressionString() + ". '" + cond1 + "' is equivalent to '" + cond2 + "'\n"
+                                            "The condition '" + cond1VerboseMsg + "' is equivalent to '" + cond2VerboseMsg + "'.";
+                    redundantConditionError(tok, msg, false);
+                    continue;
                 }
             }
 
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index e7a970e7b..ef59086d7 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -2689,6 +2689,16 @@ private:
               "  if (!x || (x && (2>(y-1)))) {}\n"
               "}");
         ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: x. '!x || (x && 2>(y-1))' is equivalent to '!x || 2>(y-1)'\n", errout.str());
+
+        check("void f(bool a, bool b) {\n"
+              "    if (a || (a && b)) {}\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: a. 'a || (a && b)' is equivalent to 'a'\n", errout.str());
+
+        check("void f(bool a, bool b) {\n"
+              "    if (a && (a || b)) {}\n"
+              "}\n");
+        ASSERT_EQUALS("[test.cpp:2]: (style) Redundant condition: a. 'a && (a || b)' is equivalent to 'a'\n", errout.str());
     }
 
     // clarify conditions with bitwise operator and comparison