From 7d84b8f1bc03d234dc586e906b69edbb5da3193d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Tue, 25 May 2021 16:13:32 +0200
Subject: [PATCH] Uninitialized variables; Fix FP when assigning struct members

---
 lib/checkuninitvar.cpp | 4 ++++
 test/testuninitvar.cpp | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index e32400738..65c1da3b5 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -1218,6 +1218,10 @@ const Token* CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer,
     // * Passing address in RHS to pointer variable
     {
         const Token *tok = derefValue ? derefValue : valueExpr;
+        if (alloc == NO_ALLOC) {
+            while (tok->valueType() && tok->valueType()->pointer == 0 && Token::simpleMatch(tok->astParent(), "."))
+                tok = tok->astParent();
+        }
         if (Token::simpleMatch(tok->astParent(), "=")) {
             if (astIsLhs(tok))
                 return nullptr;
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 5acb6289c..443a7ec25 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -3516,6 +3516,15 @@ private:
                        "}\n", "test.c");
         ASSERT_EQUALS("", errout.str());
 
+        checkUninitVar("struct Cstring { char *text; int size, alloc; };\n"
+                       "int maybe();\n"
+                       "void f() {\n"
+                       "    Cstring res;\n"
+                       "    if ( ! maybe() ) return;\n"  // <- fp goes away if this is removed
+                       "    ( ((res).text = (void*)0), ((res).size = (res).alloc = 0) );\n"  // <- fp goes away if parentheses are removed
+                       "}");
+        ASSERT_EQUALS("", errout.str());
+
         {
             const char argDirectionsTestXmlData[] = "<?xml version=\"1.0\"?>\n"
                                                     "<def>\n"