all: fix parsing and rendering cross reference

Previously, when parsing cross reference we assume that if the string
contains upper-case letter then it's a label so we store it as title
to search for ID later.

The bug is when ID is set manually and its contains upper-case for
example "[#Id]".

This changes fix this issue by storing cross reference first, not
assuming it as ID or title, and then when doing rendering we check
whether its ID or title.

4 files changed, 31 insertions, 48 deletions

diff --git a/element.go b/element.go
index 8b7a46c..c16fcce 100644
--- a/element.go
+++ b/element.go
@@ -739,15 +739,34 @@ func (el *element) toHTML(doc *Document, w io.Writer) {
 		doc.Attributes.apply(el.key, el.value)
 
 	case elKindCrossReference:
-		href, ok := el.Attrs[attrNameHref]
-		if !ok {
-			title, ok := el.Attrs[attrNameTitle]
-			if !ok {
-				title = el.Attrs[attrNameRefText]
+		var (
+			href  = el.Attrs[attrNameHref]
+			label = string(el.raw)
+		)
+		anchor := doc.anchors[href]
+		if anchor == nil {
+			href = doc.titleID[href]
+			if len(href) > 0 {
+				anchor = doc.anchors[href]
+				if anchor != nil {
+					if len(label) == 0 {
+						label = anchor.label
+					}
+				}
+			} else {
+				// href is not ID nor label, assume its broken
+				// link.
+				href = el.Attrs[attrNameHref]
+				if len(label) == 0 {
+					label = href
+				}
+			}
+		} else {
+			if len(label) == 0 {
+				label = anchor.label
 			}
-			href = doc.titleID[title]
 		}
-		fmt.Fprintf(w, "<a href=\"#%s\">%s</a>", href, el.raw)
+		fmt.Fprintf(w, "<a href=\"#%s\">%s</a>", href, label)
 
 	case elKindMacroTOC:
 		if doc.tocIsEnabled && doc.tocPosition == metaValueMacro {
diff --git a/inline_parser.go b/inline_parser.go
index 872a669..401c6b6 100644
--- a/inline_parser.go
+++ b/inline_parser.go
@@ -414,45 +414,20 @@ func (pi *inlineParser) parseCrossRef() bool {
 	var (
 		href  string
 		label string
-		title string
-		ok    bool
 	)
 
 	parts := bytes.Split(raw, []byte(","))
+	href = string(parts[0])
 	if len(parts) >= 2 {
 		label = string(bytes.TrimSpace(parts[1]))
 	}
 
-	if isRefTitle(parts[0]) {
-		// Get ID by title.
-		href, ok = pi.doc.titleID[string(parts[0])]
-		if ok {
-			if len(label) == 0 {
-				label = string(parts[0])
-			}
-		} else {
-			// Store the label for cross reference later.
-			title = string(parts[0])
-		}
-	} else if isValidID(parts[0]) {
-		href = string(parts[0])
-		if len(label) == 0 {
-			anchor := pi.doc.anchors[href]
-			if anchor != nil {
-				label = anchor.label
-			}
-		}
-	} else {
-		return false
-	}
-
-	// The ID field will we non-empty if href is empty, it will be
-	// revalidated later when rendered.
+	// Set attribute href to the first part, we will revalidated later
+	// when rendering the element.
 	elCrossRef := &element{
 		elementAttribute: elementAttribute{
 			Attrs: map[string]string{
-				attrNameHref:  href,
-				attrNameTitle: title,
+				attrNameHref: href,
 			},
 		},
 		kind: elKindCrossReference,
diff --git a/parser.go b/parser.go
index 8b0b8d5..9990b2c 100644
--- a/parser.go
+++ b/parser.go
@@ -458,17 +458,6 @@ func isLineDescriptionItem(line []byte) bool {
 	return x > 0
 }
 
-// isRefTitle will return true if one of character is upper case or white
-// space.
-func isRefTitle(s []byte) bool {
-	for _, r := range string(s) {
-		if unicode.IsUpper(r) || unicode.IsSpace(r) {
-			return true
-		}
-	}
-	return false
-}
-
 func isStyleAdmonition(style int64) bool {
 	return style&styleAdmonition > 0
 }
diff --git a/testdata/got.test.html b/testdata/got.test.html
index a688a13..854ff6f 100644
--- a/testdata/got.test.html
+++ b/testdata/got.test.html
@@ -2308,7 +2308,7 @@ D</p></td>
 <p>Cross reference with ID <a href="#_anchors">This is anchor</a>.</p>
 </div>
 <div class="paragraph">
-<p>Cross reference with block title <a href="#_anchors">Anchors</a>.</p>
+<p>Cross reference with block title <a href="#_anchors">This is anchor</a>.</p>
 </div>
 <div class="paragraph">
 <p>Cross reference with reftext <a href="#_anchors">This is anchor</a>.</p>