8332858: References with escapes have broken positions after they are transformed

Reviewed-by: vromero, jjg

src/jdk.internal.md/share/classes/jdk/internal/markdown/MarkdownTransformer.java

@@ -803,8 +803,9 @@ public class MarkdownTransformer implements JavacTrees.DocCommentTreeTransformer
                     // determine whether to use {@link ... } or {@linkplain ...}
                     // based on whether the "link text" is the same as the "link destination"
                     String ref = dest.substring(autorefScheme.length());
-                    int refPos = sourcePosToTreePos(getRefPos(ref, link));
+                    int[] span = getRefSpan(ref, link);
-                    var newRefTree = m.at(refPos).newReferenceTree(ref).setEndPos(refPos + ref.length());
+                    int refPos = sourcePosToTreePos(span[0]);
+                    var newRefTree = m.at(refPos).newReferenceTree(ref).setEndPos(sourcePosToTreePos(span[1]));
 
                     Node child = link.getFirstChild();
                     DocTree.Kind linkKind = child.getNext() == null
@@ -835,7 +836,7 @@ public class MarkdownTransformer implements JavacTrees.DocCommentTreeTransformer
          * @param ref the reference to find
          * @param link the link containing the reference
          */
-        private int getRefPos(String ref, Link link) {
+        private int[] getRefSpan(String ref, Link link) {
             var spans = link.getSourceSpans();
             var revSpanIter = spans.listIterator(spans.size());
             while (revSpanIter.hasPrevious()) {
@@ -845,11 +846,19 @@ public class MarkdownTransformer implements JavacTrees.DocCommentTreeTransformer
                 var s = source.substring(start, end);
                 var index = s.lastIndexOf(ref);
                 if (index != -1) {
-                    return start + index;
+                    return new int[] {start + index, start + index + ref.length()};
+                } else {
+                    String escapedRef = ref.replace("[]", "\\[\\]");
+                    var escapedIndex = s.lastIndexOf(escapedRef);
+                    if (escapedIndex != -1) {
+                        return new int[] {start + escapedIndex,
+                                          start + escapedIndex + escapedRef.length()};
                     }
                 }
-            return NOPOS;
             }
+            return NOSPAN;
+        }
+            private static final int[] NOSPAN = new int[] {NOPOS, NOPOS};
 
         /**
          * {@return the position in the original comment for a position in {@code source},

test/langtools/tools/javac/doctree/MarkdownTransformerPositionTest.java

@@ -23,13 +23,16 @@
 
 /*
  * @test
+ * @bug 8332858
  * @summary test case for Markdown positions
  * @run main/othervm --limit-modules jdk.compiler MarkdownTransformerPositionTest
- * @run main MarkdownTransformerPositionTest
+ * @run main MarkdownTransformerPositionTest links
  */
 
 import com.sun.source.doctree.DocCommentTree;
+import com.sun.source.doctree.LinkTree;
 import com.sun.source.doctree.RawTextTree;
+import com.sun.source.doctree.ReferenceTree;
 import com.sun.source.tree.*;
 import com.sun.source.util.*;
 
@@ -50,6 +53,10 @@ public class MarkdownTransformerPositionTest {
 
         t.simpleTest();
         t.testWithReplacements();
+
+        if (args.length > 0 && "links".equals(args[0])) {
+            t.linkWithEscapes();
+        }
     }
 
     private void simpleTest() throws Exception {
@@ -76,6 +83,16 @@ public class MarkdownTransformerPositionTest {
                 "testAuthor");
     }
 
+    private void linkWithEscapes() throws Exception {
+        runConvertedLinksTest("""
+                /// Markdown comment.
+                /// [java.util.Arrays#asList(Object\\[\\])]
+                public class Test {
+                }
+                """,
+                "java.util.Arrays#asList(Object\\[\\])");
+    }
+
     private void runTest(String source, String... expectedRawSpans) throws Exception {
         JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
         JavacTask task = (JavacTask)comp.getTask(null, null, null, null, null, Arrays.asList(new JavaSource(source)));
@@ -107,6 +124,46 @@ public class MarkdownTransformerPositionTest {
         System.err.println("Test result: success, boot modules: " + ModuleLayer.boot().modules());
     }
 
+    private void runConvertedLinksTest(String source, String... expectedRawSpans) throws Exception {
+        JavaCompiler comp = ToolProvider.getSystemJavaCompiler();
+        JavacTask task = (JavacTask)comp.getTask(null, null, null, null, null, Arrays.asList(new JavaSource(source)));
+        CompilationUnitTree cu = task.parse().iterator().next();
+        task.analyze();
+        DocTrees trees = DocTrees.instance(task);
+        List<String> rawSpans = new ArrayList<>();
+        TreePath clazzTP = new TreePath(new TreePath(cu), cu.getTypeDecls().get(0));
+        Element clazz = trees.getElement(clazzTP);
+        DocCommentTree docComment = trees.getDocCommentTree(clazz);
+
+        new DocTreeScanner<Void, Void>() {
+            @Override
+            public Void visitLink(LinkTree node, Void p) {
+                int start = (int) trees.getSourcePositions().getStartPosition(cu, docComment, node);
+                if (start != (-1)) {
+                    throw new AssertionError("UNexpected start position for synthetic link: " + start);
+                }
+                return super.visitLink(node, p);
+            }
+
+            @Override
+            public Void visitReference(ReferenceTree node, Void p) {
+                int start = (int) trees.getSourcePositions().getStartPosition(cu, docComment, node);
+                int end = (int) trees.getSourcePositions().getEndPosition(cu, docComment, node);
+                rawSpans.add(source.substring(start, end));
+                return super.visitReference(node, p);
+            }
+        }.scan(docComment, null);
+
+        List<String> expectedRawSpansList = List.of(expectedRawSpans);
+
+        if (!expectedRawSpansList.equals(rawSpans)) {
+            throw new AssertionError("Incorrect raw text spans, should be: " +
+                    expectedRawSpansList + ", but is: " + rawSpans);
+        }
+
+        System.err.println("Test result: success, boot modules: " + ModuleLayer.boot().modules());
+    }
+
     static class JavaSource extends SimpleJavaFileObject {
 
         private final String source;