Fix #14891 FP knownConditionTrueFalse (dereferencing pointer to array member) (#8704)

Co-authored-by: chrchr-github <noreply@github.com>

Author: chrchr-github

lib/valueflow.cpp

@@ -3606,6 +3606,9 @@ static void valueFlowSymbolic(const TokenList& tokenlist, const SymbolDatabase&
                 continue;
             if (tok->astOperand2()->exprId() == 0)
                 continue;
+            if (tok->astOperand2()->variable() && tok->astOperand2()->variable()->isArray() &&
+                tok->astOperand1()->valueType() && tok->astOperand1()->valueType()->pointer) // array to pointer decay
+                continue;
             if (!isConstExpression(tok->astOperand2(), settings.library))
                 continue;
             if (tok->astOperand1()->valueType() && tok->astOperand2()->valueType()) {

test/testvalueflow.cpp

@@ -9225,6 +9225,15 @@ class TestValueFlow : public TestFixture {
                "    return x;\n"
                "}\n";
         ASSERT_EQUALS(false, testValueOfX(code, 3U, "malloc(10)", 0));
+
+        code = "struct S {\n" // #14891
+               "    void f() const {\n"
+               "        const int* p = a;\n"
+               "        if (*p) {}\n"
+               "    }\n"
+               "    int a[3];\n"
+               "};\n";
+        ASSERT(tokenValues(code, "* p )").empty());
     }
 
     void valueFlowSymbolicIdentity()