Fix ImageWithCaptionAdapter.kt

Author: planarvoid

media-placeholders/src/main/java/org/wordpress/aztec/placeholders/ImageWithCaptionAdapter.kt

@@ -82,12 +82,17 @@ class ImageWithCaptionAdapter(
         private const val SRC_ATTRIBUTE = "src"
 
         suspend fun insertImageWithCaption(placeholderManager: PlaceholderManager, src: String, caption: String) {
-            placeholderManager.insertOrUpdateItem(ADAPTER_TYPE) { currentAttributes, type ->
+            placeholderManager.insertOrUpdateItem(ADAPTER_TYPE) { currentAttributes, type, placeAtStart ->
                 if (currentAttributes == null || type != ADAPTER_TYPE) {
                     mapOf(SRC_ATTRIBUTE to src, CAPTION_ATTRIBUTE to caption)
                 } else {
                     val currentCaption = currentAttributes[CAPTION_ATTRIBUTE]
-                    mapOf(SRC_ATTRIBUTE to src, CAPTION_ATTRIBUTE to "$caption - $currentCaption")
+                    val newCaption = if (placeAtStart) {
+                        "$caption - $currentCaption"
+                    } else {
+                        "$currentCaption - $caption"
+                    }
+                    mapOf(SRC_ATTRIBUTE to src, CAPTION_ATTRIBUTE to newCaption)
                 }
             }
         }