From 69371708ee9371bdaf4267529f45b9122df80c62 Mon Sep 17 00:00:00 2001
From: Filip Hrisafov <filip.hrisafov@gmail.com>
Date: Sat, 6 Jul 2024 10:31:32 +0200
Subject: [PATCH] #3574 Respect only explicit mappings but fail on unmapped
 source fields

* #3574 Respect only explicit mappings but fail on unmapped source fields

This reverts #2560, because we've decided that `@BeanMapping(ignoreByDefault = true)` should only be applied to target properties and not to source properties.
Source properties are anyway ignored, the `BeanMapping#unmappedSourcePolicy` should be used to control what should happen with unmapped source policy
---
 NEXT_RELEASE_CHANGELOG.md                           |  4 ++++
 .../ap/internal/model/BeanMappingMethod.java        |  4 ----
 ...neousSourceTargetMapperWithIgnoreByDefault.java} |  5 +++--
 .../IgnoreByDefaultSourcesTest.java                 | 13 +++++++++++--
 4 files changed, 18 insertions(+), 8 deletions(-)
 rename processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/{SourceTargetMapper.java => ErroneousSourceTargetMapperWithIgnoreByDefault.java} (74%)

diff --git a/NEXT_RELEASE_CHANGELOG.md b/NEXT_RELEASE_CHANGELOG.md
index e0f4cd31f..a6c424b08 100644
--- a/NEXT_RELEASE_CHANGELOG.md
+++ b/NEXT_RELEASE_CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ### Enhancements
 
+* Breaking change:g (#3574) - 
+This reverts #2560, because we've decided that `@BeanMapping(ignoreByDefault = true)` should only be applied to target properties and not to source properties. 
+Source properties are ignored anyway, the `BeanMapping#unmappedSourcePolicy` should be used to control what should happen with unmapped source policy
+
 ### Bugs
 
 ### Documentation
diff --git a/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java b/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
index cf5179f9c..b437afadc 100644
--- a/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
+++ b/processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java
@@ -1764,10 +1764,6 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
             if ( mappingReferences.isForForgedMethods() ) {
                 return ReportingPolicyGem.IGNORE;
             }
-            // If we have ignoreByDefault = true, unprocessed source properties are not an issue.
-            if ( method.getOptions().getBeanMapping().isignoreByDefault() ) {
-                return ReportingPolicyGem.IGNORE;
-            }
             return method.getOptions().getBeanMapping().unmappedSourcePolicy();
         }
 
diff --git a/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/SourceTargetMapper.java b/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/ErroneousSourceTargetMapperWithIgnoreByDefault.java
similarity index 74%
rename from processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/SourceTargetMapper.java
rename to processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/ErroneousSourceTargetMapperWithIgnoreByDefault.java
index e029bd739..459e2f426 100644
--- a/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/SourceTargetMapper.java
+++ b/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/ErroneousSourceTargetMapperWithIgnoreByDefault.java
@@ -14,8 +14,9 @@ import org.mapstruct.factory.Mappers;
 @Mapper(
     unmappedTargetPolicy = ReportingPolicy.IGNORE,
     unmappedSourcePolicy = ReportingPolicy.ERROR)
-public interface SourceTargetMapper {
-    SourceTargetMapper INSTANCE = Mappers.getMapper( SourceTargetMapper.class );
+public interface ErroneousSourceTargetMapperWithIgnoreByDefault {
+    ErroneousSourceTargetMapperWithIgnoreByDefault INSTANCE = Mappers.getMapper(
+        ErroneousSourceTargetMapperWithIgnoreByDefault.class );
 
     @Mapping(source = "one", target = "one")
     @BeanMapping(ignoreByDefault = true)
diff --git a/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/IgnoreByDefaultSourcesTest.java b/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/IgnoreByDefaultSourcesTest.java
index 98f2cde4c..fce6d4964 100644
--- a/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/IgnoreByDefaultSourcesTest.java
+++ b/processor/src/test/java/org/mapstruct/ap/test/ignorebydefaultsource/IgnoreByDefaultSourcesTest.java
@@ -18,8 +18,17 @@ import org.mapstruct.ap.testutil.compilation.annotation.ExpectedCompilationOutco
 public class IgnoreByDefaultSourcesTest {
 
     @ProcessorTest
-    @WithClasses({ SourceTargetMapper.class, Source.class, Target.class })
-    public void shouldSucceed() {
+    @WithClasses({ ErroneousSourceTargetMapperWithIgnoreByDefault.class, Source.class, Target.class })
+    @ExpectedCompilationOutcome(
+        value = CompilationResult.FAILED,
+        diagnostics = {
+            @Diagnostic(type = ErroneousSourceTargetMapperWithIgnoreByDefault.class,
+                kind = Kind.ERROR,
+                line = 23,
+                message = "Unmapped source property: \"other\".")
+        }
+    )
+    public void shouldRaiseErrorDueToNonIgnoredSourcePropertyWithBeanMappingIgnoreByDefault() {
     }
 
     @ProcessorTest