Casts in ternary condition

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/ExprContext.java

@@ -105,6 +105,7 @@ public abstract class ExprContext {
 
     static ExprContext newNumericContext(JTypeMirror targetType) {
         if (targetType.isPrimitive()) {
+            assert targetType.isNumeric() : targetType;
             return new RegularCtx(targetType, CtxKind.Numeric);
         }
         return RegularCtx.NO_CTX; // error

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/ast/PolyResolution.java

@@ -463,11 +463,17 @@ final class PolyResolution {
 
             return booleanCtx; // condition
 
-        } else if (papa instanceof ASTConditionalExpression && node.getIndexInParent() != 0) {
-            assert ((ASTConditionalExpression) papa).isStandalone()
-                : "Expected standalone ternary, otherwise doesCascadeContext(..) would have returned true";
+        } else if (papa instanceof ASTConditionalExpression) {
 
-            return ExprContext.newStandaloneTernaryCtx(((ASTConditionalExpression) papa).getTypeMirror());
+            if (node.getIndexInParent() == 0) {
+                return booleanCtx; // the condition
+            } else {
+                // a branch
+                assert ((ASTConditionalExpression) papa).isStandalone()
+                    : "Expected standalone ternary, otherwise doesCascadeContext(..) would have returned true";
+
+                return ExprContext.newStandaloneTernaryCtx(((ASTConditionalExpression) papa).getTypeMirror());
+            }
 
         } else if (papa instanceof ASTInfixExpression) {
             // numeric contexts, maybe
@@ -521,7 +527,10 @@ final class PolyResolution {
         if (child.getParent() != node) {
             // means the "node" is a "stop recursion because no context" result in contextOf
             return false;
-        } else if (!internalUse && node instanceof ASTConditionalExpression) {
+        } else if (!internalUse
+            && node instanceof ASTConditionalExpression
+            && child.getIndexInParent() != 0) {
+            // conditional branch
             ((ASTConditionalExpression) node).getTypeMirror(); // force resolution
             return !((ASTConditionalExpression) node).isStandalone();
         }

pmd-java/src/test/kotlin/net/sourceforge/pmd/lang/java/types/internal/infer/ConversionContextTests.kt

@@ -165,6 +165,23 @@ class ConversionContextTests : ProcessorTestSpec({
         }
     }
 
+    parserTest("Test context of ternary condition") {
+
+        val (acu, spy) = parser.parseWithTypeInferenceSpy("""
+            class Scratch {
+                static void m(Boolean boxedBool, boolean bool, String str, int[] ints) {
+                    str = (boolean) boxedBool ? "a" : "b";
+                }
+            }
+        """)
+
+        val (booleanCast) = acu.descendants(ASTCastExpression::class.java).toList()
+
+        spy.shouldBeOk {
+            booleanCast.conversionContext::getTargetType shouldBe boolean
+        }
+    }
+
     parserTest("Test numeric context") {
 
         val (acu, spy) = parser.parseWithTypeInferenceSpy("""

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/codestyle/xml/UnnecessaryCast.xml

@@ -618,7 +618,7 @@ class Scratch {
             ]]></code>
     </test-code>
     <test-code>
-        <description>Loops</description>
+        <description>Conditionals and loop statements</description>
         <expected-problems>5</expected-problems>
         <code><![CDATA[
             class Scratch {
@@ -632,6 +632,30 @@ class Scratch {
             }
             ]]></code>
     </test-code>
+    <test-code>
+        <description>Conditional expr condition</description>
+        <expected-problems>1</expected-problems>
+        <code><![CDATA[
+            class Scratch {
+                static void m(Boolean boxedBool, boolean bool, String str, int[] ints) {
+                    str = (boolean) boxedBool ? "a" : "b";
+                }
+            }
+            ]]></code>
+    </test-code>
+    <test-code>
+        <description>Necessary cast for condition</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+            class Scratch {
+                static void m(Object obj) {
+                    // both are necessary
+                    if ((Boolean) obj
+                        || (boolean) obj);
+                }
+            }
+            ]]></code>
+    </test-code>
     <test-code>
         <description>Missing context identity cast</description>
         <expected-problems>2</expected-problems>