PY-91090 Do not throw on corrupt/outdated persistent state value

(cherry picked from commit 34e5cbeb5a938dc7d4f44645e2f99b1540a6c638)

IJ-CR-216573

GitOrigin-RevId: 019909a092445fc39b07152e3e1a24505528d9c5

platform/projectModel-api/src/com/intellij/openapi/components/CustomImlComponentServiceImpl.kt

@@ -4,6 +4,8 @@ package com.intellij.openapi.components
 import com.intellij.configurationStore.deserialize
 import com.intellij.configurationStore.jdomSerializer
 import com.intellij.configurationStore.serializeObjectInto
+import com.intellij.openapi.diagnostic.rethrowControlFlowException
+import com.intellij.openapi.diagnostic.thisLogger
 import com.intellij.openapi.module.Module
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.util.JDOMUtil
@@ -17,6 +19,8 @@ import com.intellij.platform.workspace.storage.MutableEntityStorage
 import com.intellij.util.xmlb.Constants
 import com.intellij.workspaceModel.ide.legacyBridge.WorkspaceModelLegacyBridge
 import org.jdom.Element
+import java.util.concurrent.CancellationException
+import java.util.concurrent.ConcurrentHashMap
 
 private const val COMPONENT_ELEMENT: String = "component"
 
@@ -26,11 +30,24 @@ internal class CustomImlComponentServiceImpl(
 
   private val legacyBridge = WorkspaceModelLegacyBridge.getInstance(project)
 
+  /** Guards against log spam: [getComponentValue] re-deserializes on every read, so a corrupt component is reported once. */
+  private val reportedDeserializationFailures = ConcurrentHashMap.newKeySet<String>()
+
   override fun <T> getComponentValue(module: Module, componentName: String, componentClass: Class<T>): T? {
     val moduleEntity = legacyBridge.findModuleEntity(module) ?: return null
     val entity = moduleEntity.customImlComponent ?: return null
     val component = entity.components[componentName] ?: return null
-    return JDOMUtil.load(component).deserialize(componentClass)
+    // A corrupt or outdated stored value must not break every reader.
+    return try {
+      JDOMUtil.load(component).deserialize(componentClass)
+    }
+    catch (e: Exception) {
+      rethrowControlFlowException(e)
+      if (reportedDeserializationFailures.add("${module.name}#$componentName")) {
+        thisLogger().warn("Cannot deserialize custom iml component '$componentName' for module '${module.name}'; falling back to default", e)
+      }
+      null
+    }
   }
 
   override suspend fun <T> setComponentValue(module: Module, componentName: String, component: T) {

platform/workspace/jps/tests/testSrc/com/intellij/workspaceModel/ide/impl/jps/serialization/CustomImlComponentServiceTest.kt

@@ -20,6 +20,7 @@ import com.intellij.testFramework.junit5.TestDisposable
 import com.intellij.testFramework.registerOrReplaceServiceInstance
 import kotlinx.coroutines.runBlocking
 import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNull
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.extension.RegisterExtension
 import java.nio.file.Files
@@ -150,6 +151,32 @@ class CustomImlComponentServiceTest {
     }
   }
 
+  @Test
+  fun `returns null instead of throwing when stored component cannot be deserialized`() {
+    registerContributor(SecondTestModuleService.COMPONENT_NAME, disposable)
+
+    val projectPath = tempDir.newPath("corrupt-component-project")
+    Files.createDirectories(projectPath)
+
+    openProject(projectPath) { project, _ ->
+      runWriteAction {
+        ModuleManager.getInstance(project).newModule(projectPath.resolve(MODULE_FILE_NAME), EmptyModuleType.EMPTY_MODULE)
+      }
+      saveProject(project)
+    }
+
+    openProject(projectPath) { project, _ ->
+      val module = ModuleManager.getInstance(project).modules.single()
+      val componentService = project.service<CustomImlComponentService>()
+
+      runBlocking {
+        componentService.setComponentValue(module, SecondTestModuleService.COMPONENT_NAME, CorruptTestState("not-a-number"))
+      }
+
+      assertNull(componentService.getComponentValue<SecondTestModuleService.State>(module, SecondTestModuleService.COMPONENT_NAME))
+    }
+  }
+
   private fun registerContributor(componentName: String, disposable: Disposable) {
     BaseIdeSerializationContext.CUSTOM_IML_COMPONENT_NAME_CONTRIBUTOR_EP.point
       .registerExtension(TestCustomImlComponentNameContributor(componentName), disposable)
@@ -194,6 +221,12 @@ private class TestCustomImlComponentNameContributor(
   override val componentName: String,
 ) : CustomImlComponentNameContributor
 
+/**
+ * Serializes a `count` that is not an `Int`, so deserializing it back into [SecondTestModuleService.State]
+ * (whose `count` is an `Int`) fails — mimicking a stored value incompatible with the current state schema.
+ */
+internal data class CorruptTestState(var count: String = "")
+
 internal class FirstTestModuleService(private val module: Module) {
   data class State(
     var value: String = "",

python/python-syntax-core/src/com/jetbrains/python/documentation/PyDocumentationSettings.java

@@ -11,6 +11,7 @@ import com.intellij.psi.PsiFile;
 import com.intellij.psi.impl.source.PsiFileImpl;
 import com.intellij.psi.stubs.StubElement;
 import com.intellij.util.xmlb.annotations.OptionTag;
+import com.intellij.util.xmlb.annotations.Transient;
 import com.jetbrains.python.PyNames;
 import com.jetbrains.python.ast.PyAstClass;
 import com.jetbrains.python.ast.PyAstElsePart;
@@ -186,20 +187,12 @@ public abstract class PyDocumentationSettings
       return myDocStringFormat;
     }
 
-    public void setFormat(@NotNull DocStringFormat format) {
-      myDocStringFormat = format;
-    }
-
-    // Legacy name of the field to preserve settings format
-    @SuppressWarnings("unused")
-    @OptionTag("myDocStringFormat")
-    public @NotNull String getFormatName() {
-      return myDocStringFormat.getName();
-    }
-
-    @SuppressWarnings("unused")
-    public void setFormatName(@NotNull String name) {
-      myDocStringFormat = DocStringFormat.fromNameOrPlain(name);
+    public void setFormat(@Nullable DocStringFormat format) {
+      if (format == null) {
+        myDocStringFormat = DocStringFormat.PLAIN;
+      } else {
+        myDocStringFormat = format;
+      }
     }
   }
 

python/testSrc/com/intellij/python/junit5Tests/unit/alsoWin/PyDocumentationSettingsSerializationTest.kt

@@ -0,0 +1,53 @@
+// Copyright 2000-2026 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.python.junit5Tests.unit.alsoWin
+
+import com.intellij.openapi.util.JDOMUtil
+import com.intellij.testFramework.junit5.TestApplication
+import com.intellij.util.xmlb.XmlSerializer
+import com.jetbrains.python.documentation.PyDocumentationSettings.ServiceState
+import com.jetbrains.python.documentation.docstrings.DocStringFormat
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+
+/**
+ * Regression test for PY-91090: a stored docstring-format value that no valid build recognizes anymore
+ * (e.g. `format="EPYTEXT"`, removed by PY-52574) must not break deserialization of [ServiceState].
+ */
+@TestApplication
+internal class PyDocumentationSettingsSerializationTest {
+  @Test
+  fun `legacy state with removed docstring format deserializes to default instead of failing`() {
+    // Component as written by an older build: the removed EPYTEXT enum constant leaked into the "format" option
+    // (from the getFormat()/setFormat() accessor pair). Reading it used to call setFormat(null) and throw.
+    val element = JDOMUtil.load(
+      """
+      <component name="PyDocumentationSettings">
+        <option name="analyzeDoctest" value="false" />
+        <option name="renderExternalDocumentation" value="true" />
+        <option name="myDocStringFormat" value="Epytext" />
+        <option name="format" value="EPYTEXT" />
+      </component>
+      """.trimIndent()
+    )
+
+    val state = XmlSerializer.deserialize(element, ServiceState::class.java)
+
+    // The removed value falls back to PLAIN via setFormatName(); the redundant "format" option is ignored.
+    assertEquals(DocStringFormat.PLAIN, state.format)
+    assertFalse(state.myAnalyzeDoctest)
+    assertTrue(state.myRenderExternalDocumentation)
+  }
+
+  @Test
+  fun `format is no longer serialized redundantly`() {
+    val state = ServiceState(DocStringFormat.NUMPY)
+
+    val serialized = JDOMUtil.write(XmlSerializer.serialize(state))
+
+    // Only the legacy "myDocStringFormat" option persists the format; the fragile "format" option is gone.
+    assertTrue(serialized.contains("myDocStringFormat"), serialized)
+    assertFalse(serialized.contains("name=\"format\""), serialized)
+  }
+}