src/components/EventOverlay.vue

@@ -302,7 +302,9 @@ function onDragPointerMove(e) {
   } else if (st.isVirtual && (st.mode === 'resize-left' || st.mode === 'resize-right')) {
     // For virtual occurrence resize: convert to real once, then adjust range
     if (!st.realizedId) {
-      const newId = store.splitMoveVirtualOccurrence(st.id, st.startDate, st.startDate, st.endDate)
+      const initialStart = ns
+      const initialEnd = ne
+      const newId = store.splitMoveVirtualOccurrence(st.id, st.startDate, initialStart, initialEnd)
       if (newId) {
         st.realizedId = newId
         st.id = newId

src/stores/CalendarStore.js

@@ -309,6 +309,22 @@ export const useCalendarStore = defineStore('calendar', {
       const originalCountRaw = base.repeatCount
       const occurrenceDate = fromLocalString(occurrenceDateStr, DEFAULT_TZ)
       const baseStart = fromLocalString(base.startDate, DEFAULT_TZ)
+      // If series effectively has <=1 occurrence, treat as simple move (no split) and flatten
+      let totalOccurrences = Infinity
+      if (originalCountRaw !== 'unlimited') {
+        const parsed = parseInt(originalCountRaw, 10)
+        if (!isNaN(parsed)) totalOccurrences = parsed
+      }
+      if (totalOccurrences <= 1) {
+        // Flatten to non-repeating if not already
+        if (base.isRepeating) {
+          base.repeat = 'none'
+          base.isRepeating = false
+          this.events.set(baseId, { ...base })
+        }
+        this.setEventRange(baseId, newStartStr, newEndStr, { mode: 'move', rotatePattern: true })
+        return baseId
+      }
       if (occurrenceDate <= baseStart) {
         this.setEventRange(baseId, newStartStr, newEndStr, { mode: 'move' })
         return baseId
@@ -341,6 +357,11 @@ export const useCalendarStore = defineStore('calendar', {
         return
       }
       this._terminateRepeatSeriesAtIndex(baseId, keptOccurrences)
+      // After truncation compute base kept count
+      const truncated = this.events.get(baseId)
+      if (truncated && truncated.repeatCount && truncated.repeatCount !== 'unlimited') {
+        // keptOccurrences already reflects number before split; adjust not needed further
+      }
       let remainingCount = 'unlimited'
       if (originalCountRaw !== 'unlimited') {
         const total = parseInt(originalCountRaw, 10)
@@ -369,6 +390,27 @@ export const useCalendarStore = defineStore('calendar', {
         repeatCount: remainingCount,
         repeatWeekdays,
       })
+      // Flatten base if single occurrence now
+      if (truncated && truncated.isRepeating) {
+        const baseCountNum =
+          truncated.repeatCount === 'unlimited' ? Infinity : parseInt(truncated.repeatCount, 10)
+        if (baseCountNum <= 1) {
+          truncated.repeat = 'none'
+          truncated.isRepeating = false
+          this.events.set(baseId, { ...truncated })
+        }
+      }
+      // Flatten new if single occurrence only
+      const newly = this.events.get(newId)
+      if (newly && newly.isRepeating) {
+        const newCountNum =
+          newly.repeatCount === 'unlimited' ? Infinity : parseInt(newly.repeatCount, 10)
+        if (newCountNum <= 1) {
+          newly.repeat = 'none'
+          newly.isRepeating = false
+          this.events.set(newId, { ...newly })
+        }
+      }
       this.notifyEventsChanged()
       return newId
     },