Do not treat conditional-expression entries about a property fetch as proof it is initialized

src/Analyser/IssetabilityDescriptor.php

@@ -125,7 +125,7 @@ public function resolve(MutatingScope $scope, bool $useNativeTypes, Expr $expr):
 		$propertyReflection = $reflectionResolver($scope);
 		if ($propertyReflection === null) {
 			return new IssetabilityResolution(
-				IssetabilityLinkInfo::property(null, $propertyFetch, false, false, TrinaryLogic::createNo(), new NeverType(), new NeverType(), false, false, false, false, false, false, false, false),
+				IssetabilityLinkInfo::property(null, $propertyFetch, false, false, TrinaryLogic::createNo(), new NeverType(), new NeverType(), false, false, false, false, false, false, false),
 				$inner,
 			);
 		}
@@ -148,7 +148,6 @@ public function resolve(MutatingScope $scope, bool $useNativeTypes, Expr $expr):
 				$propertyReflection->getWritableType(),
 				$hasNativeType ? $propertyReflection->getNativeType() : new NeverType(),
 				$scope->hasExpressionType($propertyFetch)->yes(),
-				isset($scope->getConditionalExpressions()[$scope->getNodeKey($propertyFetch)]),
 				$initializedThisProperty,
 				$nativeReflection !== null,
 				$nativeReflection !== null && $nativeReflection->isPromoted(),

src/Analyser/IssetabilityLinkInfo.php

@@ -40,7 +40,6 @@ private function __construct(
 		private ?TrinaryLogic $isVirtual = null,
 		private ?Type $nativeType = null,
 		private bool $hasExpressionTypeOfFetch = false,
-		private bool $hasConditionalExpressionsOfFetch = false,
 		private bool $initializedThisProperty = false,
 		private bool $nativeReflectionExists = false,
 		private bool $nativeIsPromoted = false,
@@ -80,7 +79,6 @@ public static function property(
 		Type $writableType,
 		Type $nativeType,
 		bool $hasExpressionTypeOfFetch,
-		bool $hasConditionalExpressionsOfFetch,
 		bool $initializedThisProperty,
 		bool $nativeReflectionExists,
 		bool $nativeIsPromoted,
@@ -99,7 +97,6 @@ public static function property(
 			isVirtual: $isVirtual,
 			nativeType: $nativeType,
 			hasExpressionTypeOfFetch: $hasExpressionTypeOfFetch,
-			hasConditionalExpressionsOfFetch: $hasConditionalExpressionsOfFetch,
 			initializedThisProperty: $initializedThisProperty,
 			nativeReflectionExists: $nativeReflectionExists,
 			nativeIsPromoted: $nativeIsPromoted,
@@ -248,18 +245,6 @@ public function hasExpressionTypeOfFetch(): bool
 		return $this->hasExpressionTypeOfFetch;
 	}
 
-	/**
-	 * Whether the scope holds conditional-expression entries about the fetch.
-	 * Such entries exist only when the fetch was narrowed in an evaluated
-	 * condition - and evaluating a condition READS the fetch, which would have
-	 * thrown on an uninitialized typed property. A typed-property read
-	 * witnesses initialization.
-	 */
-	public function hasConditionalExpressionsOfFetch(): bool
-	{
-		return $this->hasConditionalExpressionsOfFetch;
-	}
-
 	public function isInitializedThisProperty(): bool
 	{
 		return $this->initializedThisProperty;

src/Analyser/IssetabilityResolution.php

@@ -97,7 +97,6 @@ public function isSet(callable $typeCallback, ?bool $result = null): ?bool
 				$link->hasNativeType()
 				&& !$link->isVirtual()->yes()
 				&& !$link->hasExpressionTypeOfFetch()
-				&& !$link->hasConditionalExpressionsOfFetch()
 				&& !$link->nativeHasDefaultValue()
 				&& (!$link->nativeReflectionExists() || !$link->nativeIsPromoted() || (!$link->nativeIsReadOnly() && !$link->nativeIsHooked()))
 			) {

tests/PHPStan/Rules/Variables/NullCoalesceRuleTest.php

@@ -597,4 +597,18 @@ public function testNullCoalesceAssignRightSideScope(): void
 		]);
 	}
 
+	public function testBug15046(): void
+	{
+		$this->analyse([__DIR__ . '/data/bug-15046.php'], [
+			[
+				'Property Bug15046\\BothBranches::$answer on left side of ?? is not nullable nor uninitialized.',
+				140,
+			],
+			[
+				'Property Bug15046\\ConditionMetAgain::$answer (int) on left side of ?? is not nullable.',
+				157,
+			],
+		]);
+	}
+
 }

tests/PHPStan/Rules/Variables/data/bug-15046.php

@@ -0,0 +1,161 @@
+<?php declare(strict_types = 1);
+
+namespace Bug15046;
+
+class Example {
+
+	protected int $answer;
+
+	public function echo_answer(?int $my_answer = null): void {
+		// If the following conditional property initialisation is removed, the issue disappears.
+		if ($my_answer !== null)
+			$this->answer = $my_answer;
+		// At this point, $this->answer may still be uninitialised, so that `??` is not unnecessary
+		echo "The answer is ", self::format_answer($this->answer ?? null), ".\n";
+	}
+
+	private static function format_answer(?int $the_answer): string {
+		return (string) ($the_answer ?? 'unknown');
+	}
+
+}
+
+class StaticProperty
+{
+
+	protected static int $answer;
+
+	public static function echoAnswer(?int $myAnswer = null): void
+	{
+		if ($myAnswer !== null) {
+			self::$answer = $myAnswer;
+		}
+
+		echo (self::$answer ?? null);
+	}
+
+}
+
+class BooleanCondition
+{
+
+	protected int $answer;
+
+	public function echoAnswer(bool $cond): void
+	{
+		if ($cond) {
+			$this->answer = 1;
+		}
+
+		echo ($this->answer ?? null);
+	}
+
+}
+
+class CoalesceAssign
+{
+
+	protected int $answer;
+
+	public function echoAnswer(?int $myAnswer = null): void
+	{
+		if ($myAnswer !== null) {
+			$this->answer = $myAnswer;
+		}
+
+		$this->answer ??= null;
+	}
+
+}
+
+class Ternary
+{
+
+	protected int $answer;
+
+	public function echoAnswer(?int $myAnswer = null): void
+	{
+		$myAnswer !== null ? ($this->answer = $myAnswer) : null;
+
+		echo ($this->answer ?? null);
+	}
+
+}
+
+class SwitchStatement
+{
+
+	protected int $answer;
+
+	public function echoAnswer(int $myAnswer): void
+	{
+		switch ($myAnswer) {
+			case 1:
+				$this->answer = 1;
+				break;
+		}
+
+		echo ($this->answer ?? null);
+	}
+
+}
+
+class Inner
+{
+
+	public int $deep;
+
+}
+
+class NestedChain
+{
+
+	protected Inner $inner;
+
+	public function echoAnswer(?int $myAnswer = null): void
+	{
+		$this->inner = new Inner();
+		if ($myAnswer !== null) {
+			$this->inner->deep = $myAnswer;
+		}
+
+		echo ($this->inner->deep ?? null);
+	}
+
+}
+
+class BothBranches
+{
+
+	protected int $answer;
+
+	public function echoAnswer(bool $cond): void
+	{
+		if ($cond) {
+			$this->answer = 1;
+		} else {
+			$this->answer = 2;
+		}
+
+		echo ($this->answer ?? null);
+	}
+
+}
+
+class ConditionMetAgain
+{
+
+	protected int $answer;
+
+	public function echoAnswer(?int $myAnswer = null): void
+	{
+		if ($myAnswer !== null) {
+			$this->answer = $myAnswer;
+		}
+
+		if ($myAnswer !== null) {
+			echo ($this->answer ?? null);
+		}
+	}
+
+}