IDEA-393258 javadoc: Red links when viewing references outside of source code

(cherry picked from commit ceb0485e5ee44b607aff1ec83acd8eb4c79e9f73)

GitOrigin-RevId: cc036a405d21e647d946b0cd82d9bcefcbdbf78f

java/java-impl/src/com/intellij/psi/impl/JavaPsiImplementationHelperImpl.java

@@ -531,7 +531,8 @@ public class JavaPsiImplementationHelperImpl extends JavaPsiImplementationHelper
     if (fragmentData == null) return null;
     final int offset = fragmentData.getSecond().getOffset();
 
-    final PsiElement target = fragmentData.getFirst().getContainingFile().getViewProvider().findElementAt(offset);
+    final PsiElement target =
+      JavaDocFragmentAnchorCacheKt.getMaybeSourceClass(fragmentData.getFirst()).getContainingFile().getViewProvider().findElementAt(offset);
     if (!(target instanceof PsiDocToken)) return null;
 
     return new PsiSymbolReference() {

java/java-psi-impl/src/com/intellij/codeInsight/javadoc/JavaDocFragmentAnchorCache.kt

@@ -5,6 +5,8 @@ import com.intellij.openapi.components.Service
 import com.intellij.openapi.components.service
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiClass
+import com.intellij.psi.PsiElement
+import com.intellij.psi.impl.compiled.ClsClassImpl
 import com.intellij.psi.javadoc.PsiDocComment
 import com.intellij.psi.javadoc.PsiDocFragmentName
 import com.intellij.psi.util.CachedValueProvider.Result
@@ -28,10 +30,11 @@ private class JavaDocFragmentCacheService {
   fun getAnchors(project: Project, psiClass: PsiClass): LinkedHashSet<JavaDocFragmentData> {
     val manager = CachedValuesManager.getManager(project)
     return manager.getCachedValue(psiClass) {
+      val targetClass = getMaybeSourceClass(psiClass)
       val result = LinkedHashSet<JavaDocFragmentData>().apply {
-        addAll(findIdsFromComment(psiClass.docComment))
-        for (method in psiClass.methods) addAll(findIdsFromComment(method.docComment))
-        for (field in psiClass.fields) addAll(findIdsFromComment(field.docComment))
+        addAll(findIdsFromComment(targetClass.docComment))
+        for (method in targetClass.methods) addAll(findIdsFromComment(method.docComment))
+        for (field in targetClass.fields) addAll(findIdsFromComment(field.docComment))
       }
       Result.create(result, PsiModificationTracker.MODIFICATION_COUNT)
     }
@@ -78,4 +81,15 @@ fun resolveJavaDocFragment(project: Project, fragmentName: PsiDocFragmentName):
              ?: return null
 
   return psiClass to data
+}
+
+/** Returns the source class if available for a given compiled class */
+fun getMaybeSourceClass(clazz: PsiClass): PsiClass {
+  if (clazz is ClsClassImpl) {
+    val navigationClass: PsiElement = clazz.getNavigationElement()
+    if (navigationClass is PsiClass) {
+      return navigationClass
+    }
+  }
+  return clazz
 }

java/java-psi-impl/src/com/intellij/codeInsight/javadoc/JavaDocUtil.java

@@ -199,7 +199,8 @@ public final class JavaDocUtil {
     String fragmentName = refTextCorrected.substring(fragmentIndex + 2);
     for (JavaDocFragmentData fragmentData : JavaDocFragmentAnchorCacheKt.getJavaDocFragmentsForClass(manager.getProject(), aClass)) {
       if (fragmentName.equals(fragmentData.getName())) {
-        PsiElement ref = PsiUtilCore.getElementAtOffset(aClass.getContainingFile(), fragmentData.getOffset());
+        PsiElement ref = PsiUtilCore.getElementAtOffset(JavaDocFragmentAnchorCacheKt.getMaybeSourceClass(aClass).getContainingFile(),
+                                                        fragmentData.getOffset());
         PsiDocComment docComment = PsiTreeUtil.getParentOfType(ref, PsiDocComment.class, false);
         if (docComment == null) return null;
         PsiElement owner = docComment.getOwner();