Convert .rc* versions to proper semver, then compare (github#17600)

middleware/contextualizers/enterprise-release-notes.js

@@ -1,3 +1,4 @@
+const semver = require('semver')
 const renderContent = require('../../lib/render-content')
 const patterns = require('../../lib/patterns')
 const enterpriseReleases = require('../../lib/enterprise-server-releases').supported
@@ -19,8 +20,20 @@ function sortPatchKeys (release, version) {
     })
   return keys
     .sort((a, b) => {
-      if (a.version > b.version) return -1
-      if (a.version < b.version) return 1
+      let aTemp = a.version
+      let bTemp = b.version
+
+      // There's an RC version here, so doing regular semver
+      // comparisons won't work. So, we'll convert the incompatible version
+      // strings to real semver strings, then compare.
+      const [aBase, aRc] = a.version.split('.rc')
+      if (aRc) aTemp = `${aBase}-rc.${aRc}`
+
+      const [bBase, bRc] = b.version.split('.rc')
+      if (bRc) bTemp = `${bBase}-rc.${bRc}`
+
+      if (semver.gt(aTemp, bTemp)) return -1
+      if (semver.lt(aTemp, bTemp)) return 1
       return 0
     })
 }