From 899b88754f74749c67793e4fd8a1bf259e1c04b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Marjam=C3=A4ki?= <daniel.marjamaki@gmail.com>
Date: Sat, 15 May 2021 11:16:32 +0200
Subject: [PATCH] uninitialized variables; fix false positive in loop

---
 lib/checkuninitvar.cpp |  8 +++++---
 test/testuninitvar.cpp | 14 ++++++++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/lib/checkuninitvar.cpp b/lib/checkuninitvar.cpp
index e2cdf8abf..e066901f2 100644
--- a/lib/checkuninitvar.cpp
+++ b/lib/checkuninitvar.cpp
@@ -858,9 +858,11 @@ const Token* CheckUninitVar::checkLoopBodyRecursive(const Token *start, const Va
 
         if (tok->str() == "{") {
             const Token *errorToken1 = checkLoopBodyRecursive(tok, var, alloc, membervar, bailout);
-            if (Token::simpleMatch(tok->link(), "} else {")) {
-                const Token *elseBody = tok->link()->tokAt(2);
+            tok = tok->link();
+            if (Token::simpleMatch(tok, "} else {")) {
+                const Token *elseBody = tok->tokAt(2);
                 const Token *errorToken2 = checkLoopBodyRecursive(elseBody, var, alloc, membervar, bailout);
+                tok = elseBody->link();
                 if (errorToken1 && errorToken2)
                     return errorToken1;
                 if (errorToken2)
@@ -868,7 +870,7 @@ const Token* CheckUninitVar::checkLoopBodyRecursive(const Token *start, const Va
             }
             if (bailout)
                 return nullptr;
-            if (errorToken1)
+            if (!errorToken)
                 errorToken = errorToken1;
         }
 
diff --git a/test/testuninitvar.cpp b/test/testuninitvar.cpp
index 9d39a1795..4cffef578 100644
--- a/test/testuninitvar.cpp
+++ b/test/testuninitvar.cpp
@@ -1303,6 +1303,20 @@ private:
                        "  }\n"
                        "}\n");
         ASSERT_EQUALS("[test.cpp:4]: (error) Uninitialized variable: nextEntry\n", errout.str());
+
+        checkUninitVar("void f(int x) {\n"
+                       "    list *f = NULL;\n"
+                       "    list *l;\n"
+                       "\n"
+                       "    while (--x) {\n"
+                       "        if (!f)\n"
+                       "            f = c;\n"
+                       "        else\n"
+                       "            l->next = c;\n" // <- not uninitialized
+                       "        l = c;\n"
+                       "    }\n"
+                       "}\n");
+        ASSERT_EQUALS("", errout.str());
     }
 
     // switch..