From 09a1dd43c6769fc31c728a94ca425cc3747c5f98 Mon Sep 17 00:00:00 2001
From: mike-000 <49240900+mike-000@users.noreply.github.com>
Date: Mon, 28 Sep 2020 14:05:23 +0100
Subject: [PATCH 1/2] reset to collapsible when no uncollapsible sources

---
 src/ol/control/Attribution.js | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/ol/control/Attribution.js b/src/ol/control/Attribution.js
index 12eb3c570d..733f5c2a46 100644
--- a/src/ol/control/Attribution.js
+++ b/src/ol/control/Attribution.js
@@ -175,6 +175,7 @@ class Attribution extends Control {
      */
     const visibleAttributions = [];
 
+    let collapsible = true;
     const layerStatesArray = frameState.layerStatesArray;
     for (let i = 0, ii = layerStatesArray.length; i < ii; ++i) {
       const layerState = layerStatesArray[i];
@@ -197,12 +198,8 @@ class Attribution extends Control {
         continue;
       }
 
-      if (
-        !this.overrideCollapsible_ &&
-        source.getAttributionsCollapsible() === false
-      ) {
-        this.setCollapsible(false);
-      }
+      collapsible =
+        collapsible && source.getAttributionsCollapsible() !== false;
 
       if (Array.isArray(attributions)) {
         for (let j = 0, jj = attributions.length; j < jj; ++j) {
@@ -218,6 +215,9 @@ class Attribution extends Control {
         }
       }
     }
+    if (!this.overrideCollapsible_) {
+      this.setCollapsible(collapsible);
+    }
     return visibleAttributions;
   }
 

From cb77784d2ae73c8f85babc5b058eb7524300d050 Mon Sep 17 00:00:00 2001
From: mike-000 <49240900+mike-000@users.noreply.github.com>
Date: Wed, 30 Sep 2020 10:36:53 +0100
Subject: [PATCH 2/2] also restore collapsed state to last user setting

---
 src/ol/control/Attribution.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/ol/control/Attribution.js b/src/ol/control/Attribution.js
index 733f5c2a46..682e153021 100644
--- a/src/ol/control/Attribution.js
+++ b/src/ol/control/Attribution.js
@@ -66,6 +66,12 @@ class Attribution extends Control {
     this.collapsed_ =
       options.collapsed !== undefined ? options.collapsed : true;
 
+    /**
+     * @private
+     * @type {boolean}
+     */
+    this.userCollapsed_ = this.collapsed_;
+
     /**
      * @private
      * @type {boolean}
@@ -265,6 +271,7 @@ class Attribution extends Control {
   handleClick_(event) {
     event.preventDefault();
     this.handleToggle_();
+    this.userCollapsed_ = this.collapsed_;
   }
 
   /**
@@ -300,7 +307,7 @@ class Attribution extends Control {
     }
     this.collapsible_ = collapsible;
     this.element.classList.toggle('ol-uncollapsible');
-    if (!collapsible && this.collapsed_) {
+    if (this.userCollapsed_) {
       this.handleToggle_();
     }
   }
@@ -313,6 +320,7 @@ class Attribution extends Control {
    * @api
    */
   setCollapsed(collapsed) {
+    this.userCollapsed_ = collapsed;
     if (!this.collapsible_ || this.collapsed_ === collapsed) {
       return;
     }