From 1556569a078cc1617fdcbfda7ca29c196e2d1738 Mon Sep 17 00:00:00 2001
From: chrchr-github <noreply@github.com>
Date: Mon, 5 Oct 2026 18:52:33 +0200
Subject: [PATCH] Fixup #14303: Function pointers are not known to be 1

---
 lib/astutils.cpp       |  2 +-
 lib/valueflow.cpp      |  3 +--
 test/testcondition.cpp | 10 ++++++----
 test/testvalueflow.cpp | 10 ++++++++++
 4 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/lib/astutils.cpp b/lib/astutils.cpp
index 4ebbc8644da..31c8d2e0e2d 100644
--- a/lib/astutils.cpp
+++ b/lib/astutils.cpp
@@ -1554,7 +1554,7 @@ bool isUsedAsBool(const Token* const tok, const Settings& settings)
         return true;
     if (parent->isCast())
         return !Token::simpleMatch(parent->astOperand1(), "dynamic_cast") && isUsedAsBool(parent, settings);
-    if (Token::Match(parent, "==|!=") && tok->valueType() && tok->valueType()->pointer &&
+    if (Token::Match(parent, "==|!=") && ((tok->valueType() && tok->valueType()->pointer) || tok->function()) &&
         tok->astSibling()->hasKnownIntValue() && tok->astSibling()->getKnownIntValue() == 0)
         return true;
     if (parent->str() == "(" && astIsRHS(tok) && Token::Match(parent->astOperand1(), "if|while"))
diff --git a/lib/valueflow.cpp b/lib/valueflow.cpp
index baa279803cf..c021d1d296b 100644
--- a/lib/valueflow.cpp
+++ b/lib/valueflow.cpp
@@ -5166,8 +5166,7 @@ static void valueFlowInferCondition(TokenList& tokenlist, const Settings& settin
             }
         } else if (Token::Match(tok->astParent(), "?|&&|!|%oror%") ||
                    Token::Match(tok->astParent()->previous(), "if|while (") ||
-                   (astIsPointer(tok) && isUsedAsBool(tok, settings)) ||
-                   tok->function()) {
+                   ((astIsPointer(tok) || tok->function()) && isUsedAsBool(tok, settings))) {
             std::vector<ValueFlow::Value> result = infer(makeIntegralInferModel(), "!=", tok->values(), 0);
             if (result.size() != 1)
                 continue;
diff --git a/test/testcondition.cpp b/test/testcondition.cpp
index 4d989804b36..93248837cb3 100644
--- a/test/testcondition.cpp
+++ b/test/testcondition.cpp
@@ -5518,10 +5518,12 @@ class TestCondition : public TestFixture {
               "    auto q = g;\n"
               "    if (q == nullptr) {}\n"
               "};\n");
-        ASSERT_EQUALS("[test.cpp:4:11]: (style) Condition 'p==nullptr' is always false [knownConditionTrueFalse]\n"
-                      "[test.cpp:5:11]: (style) Condition 'g==nullptr' is always false [knownConditionTrueFalse]\n"
-                      "[test.cpp:7:11]: (style) Condition 'q==nullptr' is always false [knownConditionTrueFalse]\n",
-                      errout_str());
+        TODO_ASSERT_EQUALS("[test.cpp:4:11]: (style) Condition 'p==nullptr' is always false [knownConditionTrueFalse]\n"
+                           "[test.cpp:5:11]: (style) Condition 'g==nullptr' is always false [knownConditionTrueFalse]\n"
+                           "[test.cpp:7:11]: (style) Condition 'q==nullptr' is always false [knownConditionTrueFalse]\n",
+                           "[test.cpp:4:11]: (style) Condition 'p==nullptr' is always false [knownConditionTrueFalse]\n"
+                           "[test.cpp:5:11]: (style) Condition 'g==nullptr' is always false [knownConditionTrueFalse]\n",
+                           errout_str());
     }
 
     void alwaysTrueContainer() {
diff --git a/test/testvalueflow.cpp b/test/testvalueflow.cpp
index b192a34eb7f..f84f0ea0d89 100644
--- a/test/testvalueflow.cpp
+++ b/test/testvalueflow.cpp
@@ -3286,6 +3286,16 @@ class TestValueFlow : public TestFixture {
                "    }\n"
                "};\n";
         ASSERT_EQUALS(false, testValueOfXKnown(code, 7U, 0));
+
+        code = "int g() { return 0; }\n"
+               "int f() {\n"
+               "  int (*x)() = g;\n"
+               "  return x();\n"
+               "}\n";
+        auto values = tokenValues(code, "x (");
+        ASSERT_EQUALS(1U, values.size());
+        ASSERT(values.front().isImpossible());
+        ASSERT_EQUALS(0, values.front().intvalue);
     }
 
     void valueFlowAfterSwap()