[IDEA-285910]links pointing to SETEXT and AXT in markdown file fails , after export to html.

src/commonMain/kotlin/org/intellij/markdown/flavours/commonmark/CommonMarkFlavourDescriptor.kt

@@ -76,16 +76,16 @@ open class CommonMarkFlavourDescriptor(protected val useSafeLinks: Boolean = tru
             MarkdownElementTypes.LIST_ITEM to ListItemGeneratingProvider(),
 
             MarkdownTokenTypes.SETEXT_CONTENT to TrimmingInlineHolderProvider(),
-            MarkdownElementTypes.SETEXT_1 to SimpleTagProvider("h1"),
-            MarkdownElementTypes.SETEXT_2 to SimpleTagProvider("h2"),
+            MarkdownElementTypes.SETEXT_1 to SimpleTagWithLinkProvider("h1"),
+            MarkdownElementTypes.SETEXT_2 to SimpleTagWithLinkProvider("h2"),
 
             MarkdownTokenTypes.ATX_CONTENT to TrimmingInlineHolderProvider(),
-            MarkdownElementTypes.ATX_1 to SimpleTagProvider("h1"),
-            MarkdownElementTypes.ATX_2 to SimpleTagProvider("h2"),
-            MarkdownElementTypes.ATX_3 to SimpleTagProvider("h3"),
-            MarkdownElementTypes.ATX_4 to SimpleTagProvider("h4"),
-            MarkdownElementTypes.ATX_5 to SimpleTagProvider("h5"),
-            MarkdownElementTypes.ATX_6 to SimpleTagProvider("h6"),
+            MarkdownElementTypes.ATX_1 to SimpleTagWithLinkProvider("h1"),
+            MarkdownElementTypes.ATX_2 to SimpleTagWithLinkProvider("h2"),
+            MarkdownElementTypes.ATX_3 to SimpleTagWithLinkProvider("h3"),
+            MarkdownElementTypes.ATX_4 to SimpleTagWithLinkProvider("h4"),
+            MarkdownElementTypes.ATX_5 to SimpleTagWithLinkProvider("h5"),
+            MarkdownElementTypes.ATX_6 to SimpleTagWithLinkProvider("h6"),
 
             MarkdownElementTypes.AUTOLINK to object : GeneratingProvider {
                 override fun processNode(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {

src/commonMain/kotlin/org/intellij/markdown/html/GeneratingProviders.kt

@@ -2,13 +2,14 @@ package org.intellij.markdown.html
 
 import org.intellij.markdown.MarkdownElementTypes
 import org.intellij.markdown.MarkdownTokenTypes
+import org.intellij.markdown.MarkdownTokenTypes.Companion.ATX_CONTENT
+import org.intellij.markdown.MarkdownTokenTypes.Companion.SETEXT_CONTENT
 import org.intellij.markdown.ast.*
 import org.intellij.markdown.ast.impl.ListCompositeNode
 import org.intellij.markdown.ast.impl.ListItemCompositeNode
 import org.intellij.markdown.html.entities.EntityConverter
 import org.intellij.markdown.lexer.Compat.assert
 import org.intellij.markdown.parser.LinkMap
-import kotlin.text.Regex
 
 abstract class OpenCloseGeneratingProvider : GeneratingProvider {
     abstract fun openTag(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode)
@@ -52,6 +53,54 @@ open class SimpleTagProvider(val tagName: String) : OpenCloseGeneratingProvider(
 
 }
 
+open class SimpleTagWithLinkProvider(val tagName: String) : OpenCloseGeneratingProvider() {
+
+    override fun openTag(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {
+        visitor.consumeTagOpen(
+                node,
+                tagName,
+                getPureIdString(node,text)
+        )
+    }
+
+    override fun closeTag(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {
+        visitor.consumeTagClose(tagName)
+    }
+
+    private fun getPureIdString(
+            node: ASTNode,
+            text: String
+    ) : String {
+        val stringBuilder = StringBuilder()
+        getPureIdStringDfs(
+                node,
+                text,
+                stringBuilder
+        )
+        val idValue : CharSequence = LinkMap.normalizeDestination(stringBuilder.toString().trim(), true)
+        return "id = \"$idValue\""
+    }
+
+    private fun getPureIdStringDfs(
+            node: ASTNode,
+            text: String,
+            stringBuilder: StringBuilder
+    ) {
+        if (node.type in listOf(SETEXT_CONTENT, ATX_CONTENT)) {
+            stringBuilder.append(text.substring(node.startOffset, node.endOffset))
+        } else {
+            for(children in node.children){
+                getPureIdStringDfs(
+                        children,
+                        text,
+                        stringBuilder
+                )
+            }
+        }
+    }
+
+}
+
 open class SimpleInlineTagProvider(val tagName: String, val renderFrom: Int = 0, val renderTo: Int = 0)
 : InlineHolderGeneratingProvider() {
     override fun openTag(visitor: HtmlGenerator.HtmlGeneratingVisitor, text: String, node: ASTNode) {

src/fileBasedTest/resources/data/html/headers.md

@@ -10,3 +10,10 @@ This is *header* lvl2
 #### ATX4 *em* ATX4 ####
 ##### ATX5 *em* ATX5 #####
 ###### ATX6 *em* ATX6 ######
+
+###### ATX6_0<>&=
+###### ATX6_1
+
+[link ATX6_0<>&=](#ATX6_0<>&=)
+
+[link ATX6_1](#ATX6_1)