Try again before avoiding death by recursion

kewisch · Apr 15, 2024 · 4620888 · 4620888
1 parent eaf5b23
commit 4620888
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Showing 3 changed files with 39 additions and 8 deletions.
diff --git a/lib/ical/recur.js b/lib/ical/recur.js
@@ -103,12 +103,13 @@ class Recur {
 
       if (ucname in partDesign) {
         let partArr = value.split(',');
-        let partArrIdx = 0;
-        let partArrLen = partArr.length;
+        let partSet = new Set();
 
-        for (; partArrIdx < partArrLen; partArrIdx++) {
-          partArr[partArrIdx] = partDesign[ucname](partArr[partArrIdx]);
+        for (let part of partArr) {
+          partSet.add(partDesign[ucname](part));
         }
+        partArr = [...partSet];
+
         dict[name] = (partArr.length == 1 ? partArr[0] : partArr);
       } else if (ucname in optionDesign) {
         optionDesign[ucname](value, dict, fmtIcal);

diff --git a/lib/ical/recur_iterator.js b/lib/ical/recur_iterator.js
@@ -341,7 +341,7 @@ class RecurIterator {
    * Retrieve the next occurrence from the iterator.
    * @return {ICAL.Time}
    */
-  next() {
+  next(again = false) {
     let before = (this.last ? this.last.clone() : null);
 
     if ((this.rule.count && this.occurrence_number >= this.rule.count) ||
@@ -395,10 +395,11 @@ class RecurIterator {
              this.last.compare(this.dtstart) < 0 ||
              !valid);
 
-    // TODO is this valid?
     if (this.last.compare(before) == 0) {
-      throw new Error("Same occurrence found twice, protecting " +
-                      "you from death by recursion");
+      if (again) {
+        throw new Error("Same occurrence found twice, protecting you from death by recursion");
+      }
+      this.next(true);
     }
 
     if (this.rule.until && this.last.compare(this.rule.until) > 0) {

diff --git a/test/recur_iterator_test.js b/test/recur_iterator_test.js
@@ -613,6 +613,35 @@ suite('recur_iterator', function() {
         ]
       });
 
+      // Last day and 31st day of the month. The last day could be the 31st,
+      // and this shouldn't throw an error.
+      testRRULE('FREQ=MONTHLY;BYMONTHDAY=-1,31', {
+        dtStart: '2022-01-01T08:00:00',
+        dates: [
+          '2022-01-31T08:00:00',
+          '2022-02-28T08:00:00',
+          '2022-03-31T08:00:00',
+          '2022-04-30T08:00:00',
+          '2022-05-31T08:00:00',
+          '2022-06-30T08:00:00'
+        ]
+      });
+
+      // 31st day of the month, specified more than once. The repeated values
+      // should be collapsed to one.
+      testRRULE('FREQ=MONTHLY;BYMONTHDAY=31,31,31,31', {
+        dtStart: '2022-01-01T08:00:00',
+        dates: [
+          '2022-01-31T08:00:00',
+          '2022-03-31T08:00:00',
+          '2022-05-31T08:00:00',
+          '2022-07-31T08:00:00',
+          '2022-08-31T08:00:00',
+          '2022-10-31T08:00:00',
+          '2022-12-31T08:00:00',
+        ]
+      });
+
       // Last day of the month, monthly.
       testRRULE('FREQ=MONTHLY;BYMONTHDAY=-1', {
         dtStart: '2015-01-01T08:00:00',