From fa067724d71b5192ec2ae16b5d8749d6118129ef Mon Sep 17 00:00:00 2001
From: "ouyang.wei.victor" <ouyang.wei.victor@vertiv.com>
Date: Mon, 24 Aug 2026 18:05:50 +0800
Subject: [PATCH] Detect uninitvar when variable is used as ternary condition

isVariableUsage() did not treat a variable appearing as the condition of
a ternary operator as a read, because '?' is an eExtendedOp token and is
therefore rejected by Token::isOp(). The scope analysis then assumed the
variable was assigned and stopped, so `x = flag ? 10 : 0;` was silently
accepted while `if (flag)` was correctly reported.

Fixes #90
---
 samples/cpp/uninitvar.cpp    | 11 +++++++++++
 trunk/lib/checkuninitvar.cpp |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/samples/cpp/uninitvar.cpp b/samples/cpp/uninitvar.cpp
index 9337b85..45b79b0 100644
--- a/samples/cpp/uninitvar.cpp
+++ b/samples/cpp/uninitvar.cpp
@@ -7,4 +7,15 @@ void Demo(int b)
 	}
 	// 缺少else分支，变量a可能不会初始化
 	a++;
+}
+
+unsigned short TernaryDemo(unsigned short input)
+{
+	unsigned char flag;
+	if (input > 0)
+	{
+		flag = 1;
+	}
+	// 三目运算符的条件会读取变量flag
+	return flag ? 10 : 0;
 }
\ No newline at end of file
diff --git a/trunk/lib/checkuninitvar.cpp b/trunk/lib/checkuninitvar.cpp
index 4f42bff..b760e97 100644
--- a/trunk/lib/checkuninitvar.cpp
+++ b/trunk/lib/checkuninitvar.cpp
@@ -781,6 +781,10 @@ int CheckUninitVar::isVariableUsage(const Token *vartok, bool pointer, Alloc all
         return (var && var->typeStartToken()->isStandardType());
     }
 
+    const Token *parent = vartok->astParent();
+    if (alloc == NO_ALLOC && Token::simpleMatch(parent, "?") && parent->astOperand1() == vartok)
+        return true;
+
     if (alloc == NO_ALLOC && vartok->next() && vartok->next()->isOp() && !vartok->next()->isAssignmentOp())
         return true;