From e12a733ee97cb225bb1c60222b664c1f1abd7043 Mon Sep 17 00:00:00 2001
From: Paul Fultz II <pfultz2@yahoo.com>
Date: Wed, 23 Dec 2020 06:37:28 -0600
Subject: [PATCH] Fix issue 10053: False positive: Same value on both branches
 of ternary operator (#2962)

---
 lib/astutils.cpp   | 41 +++++++++++++++++++++++++++++++++--------
 lib/valueflow.h    |  2 +-
 test/testother.cpp | 17 +++++++++++++++++
 3 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 2e8ac921c..0dcc49807 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -741,26 +741,51 @@ static void findTokenValue(const Token* const tok, std::function<bool(const Valu
         f(*x);
 }
 
-bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
+static bool isSameLifetime(const Token * const tok1, const Token * const tok2)
+{
+    ValueFlow::Value v1 = getLifetimeObjValue(tok1);
+    ValueFlow::Value v2 = getLifetimeObjValue(tok2);
+    if (!v1.isLifetimeValue() || !v2.isLifetimeValue())
+        return false;
+    return v1.tokvalue == v2.tokvalue;
+}
+
+static bool compareKnownValue(const Token * const tok1, const Token * const tok2, std::function<bool(const ValueFlow::Value&, const ValueFlow::Value&, bool)> compare)
 {
     bool result = false;
+    bool sameLifetime = isSameLifetime(tok1, tok2);
     findTokenValue(tok1, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v1) {
+        if (v1.isNonValue() || v1.isContainerSizeValue())
+            return;
         findTokenValue(tok2, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v2) {
-            result = v1.equalValue(v2);
+            if (v1.valueType == v2.valueType) {
+                result = compare(v1, v2, sameLifetime);
+            }
         });
     });
     return result;
 }
 
+bool isEqualKnownValue(const Token * const tok1, const Token * const tok2)
+{
+    return compareKnownValue(tok1, tok2, [&](const ValueFlow::Value& v1, const ValueFlow::Value& v2, bool sameLifetime) {
+        bool r = v1.equalValue(v2);
+        if (v1.isIteratorValue()) {
+            r &= sameLifetime;
+        }
+        return r;
+    });
+}
+
 bool isDifferentKnownValues(const Token * const tok1, const Token * const tok2)
 {
-    bool result = false;
-    findTokenValue(tok1, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v1) {
-        findTokenValue(tok2, std::mem_fn(&ValueFlow::Value::isKnown), [&](const ValueFlow::Value& v2) {
-            result = !v1.equalValue(v2);
-        });
+    return compareKnownValue(tok1, tok2, [&](const ValueFlow::Value& v1, const ValueFlow::Value& v2, bool sameLifetime) {
+        bool r = v1.equalValue(v2);
+        if (v1.isIteratorValue()) {
+            r &= sameLifetime;
+        }
+        return !r;
     });
-    return result;
 }
 
 static bool isSameConstantValue(bool macro, const Token * const tok1, const Token * const tok2)
diff --git a/lib/valueflow.h b/lib/valueflow.h
index edbc5ea71..e799d69ad 100644
--- a/lib/valueflow.h
+++ b/lib/valueflow.h
@@ -399,6 +399,6 @@ std::string lifetimeType(const Token *tok, const ValueFlow::Value *val);
 
 std::string lifetimeMessage(const Token *tok, const ValueFlow::Value *val, ValueFlow::Value::ErrorPath &errorPath);
 
-ValueFlow::Value getLifetimeObjValue(const Token *tok, bool inconclusive = false);
+CPPCHECKLIB ValueFlow::Value getLifetimeObjValue(const Token *tok, bool inconclusive = false);
 
 #endif // valueflowH
diff --git a/test/testother.cpp b/test/testother.cpp
index 16b365d6c..cfe2ddb8b 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -5340,6 +5340,23 @@ private:
 
         check("int f8(int a) {return (a == (int)1) ? 1 : 1; }");
         ASSERT_EQUALS("[test.cpp:1]: (style) Same value in both branches of ternary operator.\n", errout.str());
+
+        check("struct Foo {\n"
+              "  std::vector<int> bar{1,2,3};\n"
+              "  std::vector<int> baz{4,5,6};\n"
+              "};\n"
+              "void f() {\n"
+              "  Foo foo;\n"
+              "  it = true ? foo.bar.begin() : foo.baz.begin();\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
+
+        check("void f(bool b) {\n"
+              "  std::vector<int> bar{1,2,3};\n"
+              "  std::vector<int> baz{4,5,6};\n"
+              "  std::vector<int> v = b ? bar : baz;\n"
+              "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     void duplicateExpressionTemplate() { // #6930