From d33d29ce6364f8558048967d1ca789ff8b72a6cd Mon Sep 17 00:00:00 2001
From: olabetskyi <153490942+olabetskyi@users.noreply.github.com>
Date: Mon, 10 Jun 2024 16:24:06 +0300
Subject: [PATCH] Union Assignment fix (#6501)

---
 lib/fwdanalysis.cpp |  2 +-
 test/testother.cpp  | 14 ++++++++++++--
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/lib/fwdanalysis.cpp b/lib/fwdanalysis.cpp
index 500538efee3..5a0bf28638d 100644
--- a/lib/fwdanalysis.cpp
+++ b/lib/fwdanalysis.cpp
@@ -327,7 +327,7 @@ FwdAnalysis::Result FwdAnalysis::checkRecursive(const Token *expr, const Token *
                 if (parent->variable() && parent->variable()->type() && parent->variable()->type()->isUnionType() && parent->varId() == expr->varId()) {
                     while (parent && Token::simpleMatch(parent->astParent(), "."))
                         parent = parent->astParent();
-                    if (parent && parent->valueType() && Token::Match(parent->astParent(), "%assign%") && !Token::Match(parent->astParent()->astParent(), "%assign%") && parent->astParent()->astOperand1() == parent) {
+                    if (parent && parent->valueType() && Token::simpleMatch(parent->astParent(), "=") && !Token::Match(parent->astParent()->astParent(), "%assign%") && parent->astParent()->astOperand1() == parent) {
                         const Token * assignment = parent->astParent()->astOperand2();
                         while (Token::simpleMatch(assignment, ".") && assignment->varId() != expr->varId())
                             assignment = assignment->astOperand1();
diff --git a/test/testother.cpp b/test/testother.cpp
index 462b32247fd..75cec25b539 100644
--- a/test/testother.cpp
+++ b/test/testother.cpp
@@ -4535,8 +4535,7 @@ class TestOther : public TestFixture {
         ASSERT_EQUALS("", errout_str());
 
         // Ticket #10093 "redundantAssignment when using a union"
-        check("#include <stdio.h>\n"
-              "typedef union{\n"
+        check("typedef union{\n"
               "    char as_char[4];\n"
               "    int as_int;\n"
               "} union_t;\n"
@@ -4552,6 +4551,17 @@ class TestOther : public TestFixture {
               "    u.as_int = 0;\n"
               "}", true, false, false);
         ASSERT_EQUALS("", errout_str());
+
+        // Ticket #5115 "redundantAssignment when using a union"
+        check("void foo(char *ptr) {\n"
+              "    union {\n"
+              "        char * s8;\n"
+              "        unsigned long long u64;\n"
+              "    } addr;\n"
+              "    addr.s8 = ptr;\n"
+              "    addr.u64 += 8;\n"
+              "}", true, false, false);
+        ASSERT_EQUALS("", errout_str());
     }
 
     void switchRedundantOperationTest() {