From 67d858983c5bde3cd8ce432da5d92b812884a8e6 Mon Sep 17 00:00:00 2001
From: TitiAlone <talone@boxph.one>
Date: Mon, 8 Mar 2021 22:30:12 +0100
Subject: [PATCH 1/2] [zmarkdown] Add a test case for #431

---
 .../zmarkdown/__tests__/regressions.test.js   | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/packages/zmarkdown/__tests__/regressions.test.js b/packages/zmarkdown/__tests__/regressions.test.js
index 3e7d9382e..776e6bbcd 100644
--- a/packages/zmarkdown/__tests__/regressions.test.js
+++ b/packages/zmarkdown/__tests__/regressions.test.js
@@ -26,6 +26,41 @@ describe('Regression tests', () => {
       const [rendered] = response.data
       expect(rendered).toMatchSnapshot()
     })
+
+    test('#431 It uses random footnote postfix correctly', async () => {
+      const md = dedent`
+        hello[^foo] world[^bar]
+
+        [^foo]: foo
+        [^bar]: bar
+      `
+
+      const firstResponse = await a.post(html, {
+        md,
+        opts: {},
+      })
+
+      const secondResponse = await a.post(html, {
+        md,
+        opts: {},
+      })
+
+      const [firstRendered] = firstResponse.data
+      const [secondRendered] = secondResponse.data
+
+      const firstFooReference = firstRendered.match(/fnref-1-([a-zA-Z0-9-_]+)/)
+      const firstFooDefinition = firstRendered.match(/fn-1-([a-zA-Z0-9-_]+)/)
+      const firstBarReference = firstRendered.match(/fnref-2-([a-zA-Z0-9-_]+)/)
+      const secondBarDefinition = secondRendered.match(/fn-2-([a-zA-Z0-9-_]+)/)
+
+      // A unique token shall be generated for a given footnote
+      expect(firstFooReference[1]).toEqual(firstFooDefinition[1])
+      // But also for a given render
+      expect(firstFooReference[1]).toEqual(firstBarReference[1])
+
+      // Finally, we expect tokens to differ between two successive renderings
+      expect(secondBarDefinition[1]).not.toEqual(firstBarReference[1])
+    })
   })
 
   describe('Latex endpoint', () => {

From 352a34f73d66d64f3386569cb510ee56b1f37457 Mon Sep 17 00:00:00 2001
From: TitiAlone <talone@boxph.one>
Date: Mon, 8 Mar 2021 22:31:04 +0100
Subject: [PATCH 2/2] [zmarkdown] Fix too much randomness in footnotes

---
 packages/zmarkdown/common.js            | 6 ++++++
 packages/zmarkdown/config/html/index.js | 8 +++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/packages/zmarkdown/common.js b/packages/zmarkdown/common.js
index b252d4a6d..5b625ba73 100644
--- a/packages/zmarkdown/common.js
+++ b/packages/zmarkdown/common.js
@@ -33,10 +33,15 @@ module.exports = (
     parser.use(processor, processorConfig)
   }
 
+  // Regenerate footnotes postfix on extracts
+  const doRegenerate = (processor === 'html' && processorConfig._regenerateFootnotePostfix)
+  const regenerator = processorConfig._regenerateFootnotePostfix
+
   return (input, cb) => {
     if (typeof cb !== 'function') {
       return new Promise((resolve, reject) =>
         parser.process(input, (err, vfile) => {
+          if (doRegenerate) regenerator()
           if (err) return reject(err)
 
           resolve(vfile)
@@ -44,6 +49,7 @@ module.exports = (
     }
 
     parser.process(input, (err, vfile) => {
+      if (doRegenerate) regenerator()
       if (err) return cb(err)
 
       cb(null, vfile)
diff --git a/packages/zmarkdown/config/html/index.js b/packages/zmarkdown/config/html/index.js
index 268d7d4c0..9108c7c93 100644
--- a/packages/zmarkdown/config/html/index.js
+++ b/packages/zmarkdown/config/html/index.js
@@ -1,5 +1,7 @@
 const shortid = require('shortid')
 
+let currentFootnotePostfix = shortid.generate()
+
 module.exports = {
   autolinkHeadings: {
     behaviour: 'append',
@@ -22,7 +24,11 @@ module.exports = {
 
   sanitize: require('../sanitize'),
 
-  postfixFootnotes: (agg) => `${agg}-${shortid.generate()}`,
+  postfixFootnotes: (agg) => `${agg}-${currentFootnotePostfix}`,
+
+  _regenerateFootnotePostfix: () => {
+    currentFootnotePostfix = shortid.generate()
+  },
 
   postProcessors: {
     iframeWrappers:   require('./iframe-wrappers'),