Fix #300

_benchmark/cmark/Makefile

@@ -19,7 +19,7 @@ run: $(CMARK_BIN)
 		GOOS=windows GOARCH=amd64 go build -o goldmark_benchmark.exe ./goldmark_benchmark.go && ./goldmark_benchmark.exe; \
 	fi
 
-./cmark-master/build/src/config.h:
+./cmark-master/Makefile:
 	wget -nc -O cmark.zip https://github.com/commonmark/cmark/archive/master.zip
 	unzip cmark.zip
 	rm -f cmark.zip
@@ -29,7 +29,7 @@ run: $(CMARK_BIN)
 		cd cmark-master && make mingw; \
 	fi
 
-$(CMARK_BIN): ./cmark-master/build/src/config.h
+$(CMARK_BIN): ./cmark-master/Makefile
 	@ if [ -z "$${WSL_INTEROP}" ]; then \
 		gcc -I./cmark-master/build/src -I./cmark-master/src  cmark_benchmark.c -o $(CMARK_BIN) -L./cmark-master/build/src -lcmark; \
 	else \

extension/_test/footnote.txt

@@ -66,3 +66,26 @@ test![^1]
 </ol>
 </section>
 //= = = = = = = = = = = = = = = = = = = = = = = =//
+
+6: Multiple references to the same footnotes should have different ids
+//- - - - - - - - -//
+something[^fn:1]
+
+something[^fn:1]
+
+something[^fn:1]
+
+[^fn:1]: footnote text
+//- - - - - - - - -//
+<p>something<sup id="fnref:1"><a href="#fn:1" class="footnote-ref" role="doc-noteref">1</a></sup></p>
+<p>something<sup id="fnref1:1"><a href="#fn:1" class="footnote-ref" role="doc-noteref">1</a></sup></p>
+<p>something<sup id="fnref2:1"><a href="#fn:1" class="footnote-ref" role="doc-noteref">1</a></sup></p>
+<section class="footnotes" role="doc-endnotes">
+<hr>
+<ol>
+<li id="fn:1" role="doc-endnote">
+<p>footnote text&#160;<a href="#fnref:1" class="footnote-backref" role="doc-backlink">&#x21a9;&#xfe0e;</a>&#160;<a href="#fnref1:1" class="footnote-backref" role="doc-backlink">&#x21a9;&#xfe0e;</a>&#160;<a href="#fnref2:1" class="footnote-backref" role="doc-backlink">&#x21a9;&#xfe0e;</a></p>
+</li>
+</ol>
+</section>
+//= = = = = = = = = = = = = = = = = = = = = = = =//

extension/ast/footnote.go

@@ -12,6 +12,7 @@ type FootnoteLink struct {
 	gast.BaseInline
 	Index    int
 	RefCount int
+	RefIndex int
 }
 
 // Dump implements Node.Dump.
@@ -19,6 +20,7 @@ func (n *FootnoteLink) Dump(source []byte, level int) {
 	m := map[string]string{}
 	m["Index"] = fmt.Sprintf("%v", n.Index)
 	m["RefCount"] = fmt.Sprintf("%v", n.RefCount)
+	m["RefIndex"] = fmt.Sprintf("%v", n.RefIndex)
 	gast.DumpHelper(n, source, level, m, nil)
 }
 
@@ -35,6 +37,7 @@ func NewFootnoteLink(index int) *FootnoteLink {
 	return &FootnoteLink{
 		Index:    index,
 		RefCount: 0,
+		RefIndex: 0,
 	}
 }
 
@@ -44,6 +47,7 @@ type FootnoteBacklink struct {
 	gast.BaseInline
 	Index    int
 	RefCount int
+	RefIndex int
 }
 
 // Dump implements Node.Dump.
@@ -51,6 +55,7 @@ func (n *FootnoteBacklink) Dump(source []byte, level int) {
 	m := map[string]string{}
 	m["Index"] = fmt.Sprintf("%v", n.Index)
 	m["RefCount"] = fmt.Sprintf("%v", n.RefCount)
+	m["RefIndex"] = fmt.Sprintf("%v", n.RefIndex)
 	gast.DumpHelper(n, source, level, m, nil)
 }
 
@@ -67,6 +72,7 @@ func NewFootnoteBacklink(index int) *FootnoteBacklink {
 	return &FootnoteBacklink{
 		Index:    index,
 		RefCount: 0,
+		RefIndex: 0,
 	}
 }
 

extension/footnote.go

@@ -2,6 +2,7 @@ package extension
 
 import (
 	"bytes"
+	"fmt"
 	"strconv"
 
 	"github.com/yuin/goldmark"
@@ -217,8 +218,14 @@ func (a *footnoteASTTransformer) Transform(node *gast.Document, reader text.Read
 				counter[fnlink.Index]++
 			}
 		}
+		refCounter := map[int]int{}
 		for _, fnlink := range fnlist {
 			fnlink.RefCount = counter[fnlink.Index]
+			if _, ok := refCounter[fnlink.Index]; !ok {
+				refCounter[fnlink.Index] = 0
+			}
+			fnlink.RefIndex = refCounter[fnlink.Index]
+			refCounter[fnlink.Index]++
 		}
 	}
 	for footnote := list.FirstChild(); footnote != nil; {
@@ -232,9 +239,19 @@ func (a *footnoteASTTransformer) Transform(node *gast.Document, reader text.Read
 		if index < 0 {
 			list.RemoveChild(list, footnote)
 		} else {
+			refCount := counter[index]
 			backLink := ast.NewFootnoteBacklink(index)
-			backLink.RefCount = counter[index]
+			backLink.RefCount = refCount
+			backLink.RefIndex = 0
 			container.AppendChild(container, backLink)
+			if refCount > 1 {
+				for i := 1; i < refCount; i++ {
+					backLink := ast.NewFootnoteBacklink(index)
+					backLink.RefCount = refCount
+					backLink.RefIndex = i
+					container.AppendChild(container, backLink)
+				}
+			}
 		}
 		footnote = next
 	}
@@ -514,7 +531,11 @@ func (r *FootnoteHTMLRenderer) renderFootnoteLink(w util.BufWriter, source []byt
 		is := strconv.Itoa(n.Index)
 		_, _ = w.WriteString(`<sup id="`)
 		_, _ = w.Write(r.idPrefix(node))
-		_, _ = w.WriteString(`fnref:`)
+		_, _ = w.WriteString(`fnref`)
+		if n.RefIndex > 0 {
+			_, _ = w.WriteString(fmt.Sprintf("%v", n.RefIndex))
+		}
+		_ = w.WriteByte(':')
 		_, _ = w.WriteString(is)
 		_, _ = w.WriteString(`"><a href="#`)
 		_, _ = w.Write(r.idPrefix(node))
@@ -541,7 +562,11 @@ func (r *FootnoteHTMLRenderer) renderFootnoteBacklink(w util.BufWriter, source [
 		is := strconv.Itoa(n.Index)
 		_, _ = w.WriteString(`&#160;<a href="#`)
 		_, _ = w.Write(r.idPrefix(node))
-		_, _ = w.WriteString(`fnref:`)
+		_, _ = w.WriteString(`fnref`)
+		if n.RefIndex > 0 {
+			_, _ = w.WriteString(fmt.Sprintf("%v", n.RefIndex))
+		}
+		_ = w.WriteByte(':')
 		_, _ = w.WriteString(is)
 		_, _ = w.WriteString(`" class="`)
 		_, _ = w.Write(applyFootnoteTemplate(r.FootnoteConfig.BacklinkClass, n.Index, n.RefCount))

extension/footnote_test.go

@@ -63,20 +63,19 @@ Another one.[^2]
 [^2]: Another footnote.
 `,
 			Expected: `<p>That's some text with a footnote.<sup id="article12-fnref:1"><a href="#article12-fn:1" class="link-class" title="link-title-2-1" role="doc-noteref">1</a></sup></p>
-<p>Same footnote.<sup id="article12-fnref:1"><a href="#article12-fn:1" class="link-class" title="link-title-2-1" role="doc-noteref">1</a></sup></p>
+<p>Same footnote.<sup id="article12-fnref1:1"><a href="#article12-fn:1" class="link-class" title="link-title-2-1" role="doc-noteref">1</a></sup></p>
 <p>Another one.<sup id="article12-fnref:2"><a href="#article12-fn:2" class="link-class" title="link-title-1-2" role="doc-noteref">2</a></sup></p>
 <section class="footnotes" role="doc-endnotes">
 <hr>
 <ol>
 <li id="article12-fn:1" role="doc-endnote">
-<p>And that's the footnote.&#160;<a href="#article12-fnref:1" class="backlink-class" title="backlink-title" role="doc-backlink">^</a></p>
+<p>And that's the footnote.&#160;<a href="#article12-fnref:1" class="backlink-class" title="backlink-title" role="doc-backlink">^</a>&#160;<a href="#article12-fnref1:1" class="backlink-class" title="backlink-title" role="doc-backlink">^</a></p>
 </li>
 <li id="article12-fn:2" role="doc-endnote">
 <p>Another footnote.&#160;<a href="#article12-fnref:2" class="backlink-class" title="backlink-title" role="doc-backlink">^</a></p>
 </li>
 </ol>
-</section>
+</section>`,
-`,
 		},
 		t,
 	)
@@ -123,20 +122,19 @@ Another one.[^2]
 [^2]: Another footnote.
 `,
 			Expected: `<p>That's some text with a footnote.<sup id="article12-fnref:1"><a href="#article12-fn:1" class="link-class" title="link-title-2-1" role="doc-noteref">1</a></sup></p>
-<p>Same footnote.<sup id="article12-fnref:1"><a href="#article12-fn:1" class="link-class" title="link-title-2-1" role="doc-noteref">1</a></sup></p>
+<p>Same footnote.<sup id="article12-fnref1:1"><a href="#article12-fn:1" class="link-class" title="link-title-2-1" role="doc-noteref">1</a></sup></p>
 <p>Another one.<sup id="article12-fnref:2"><a href="#article12-fn:2" class="link-class" title="link-title-1-2" role="doc-noteref">2</a></sup></p>
 <section class="footnotes" role="doc-endnotes">
 <hr>
 <ol>
 <li id="article12-fn:1" role="doc-endnote">
-<p>And that's the footnote.&#160;<a href="#article12-fnref:1" class="backlink-class" title="backlink-title" role="doc-backlink">^</a></p>
+<p>And that's the footnote.&#160;<a href="#article12-fnref:1" class="backlink-class" title="backlink-title" role="doc-backlink">^</a>&#160;<a href="#article12-fnref1:1" class="backlink-class" title="backlink-title" role="doc-backlink">^</a></p>
 </li>
 <li id="article12-fn:2" role="doc-endnote">
 <p>Another footnote.&#160;<a href="#article12-fnref:2" class="backlink-class" title="backlink-title" role="doc-backlink">^</a></p>
 </li>
 </ol>
-</section>
+</section>`,
-`,
 		},
 		t,
 	)