From f85de946e63b4668716bceddade50b772037d6c3 Mon Sep 17 00:00:00 2001
From: Ingo Weyrich <heckflosse67@gmx.de>
Date: Tue, 30 Jul 2019 14:44:18 +0200
Subject: [PATCH] Fix some corner cases in thumb selection, #5393

---
 rtgui/filebrowser.cc      | 25 ++++++++++++++++---------
 rtgui/thumbbrowserbase.cc | 20 +++++++++++---------
 2 files changed, 27 insertions(+), 18 deletions(-)

diff --git a/rtgui/filebrowser.cc b/rtgui/filebrowser.cc
index b968a285e..eb85613ee 100644
--- a/rtgui/filebrowser.cc
+++ b/rtgui/filebrowser.cc
@@ -783,16 +783,20 @@ void FileBrowser::menuItemActivated (Gtk::MenuItem* m)
         {
             MYWRITERLOCK(l, entryRW);
 
-            selected.clear ();
+            selected.clear();
 
-            for (size_t i = 0; i < fd.size(); i++)
-                if (checkFilter (fd[i])) {
+            for (size_t i = 0; i < fd.size(); ++i) {
+                if (checkFilter(fd[i])) {
                     fd[i]->selected = true;
-                    selected.push_back (fd[i]);
+                    selected.push_back(fd[i]);
                 }
+            }
+            if (!anchor && !selected.empty()) {
+                anchor = selected[0];
+            }
         }
         queue_draw ();
-        notifySelectionListener ();
+        notifySelectionListener();
     } else if( m == copyTo) {
         tbl->copyMoveRequested (mselected, false);
     }
@@ -1438,12 +1442,12 @@ void FileBrowser::applyFilter (const BrowserFilter& filter)
         }
 
         for (size_t i = 0; i < fd.size(); i++) {
-            if (checkFilter (fd[i])) {
+            if (checkFilter(fd[i])) {
                 numFiltered++;
-            } else if (fd[i]->selected ) {
+            } else if (fd[i]->selected) {
                 fd[i]->selected = false;
-                std::vector<ThumbBrowserEntryBase*>::iterator j = std::find (selected.begin(), selected.end(), fd[i]);
-                selected.erase (j);
+                std::vector<ThumbBrowserEntryBase*>::iterator j = std::find(selected.begin(), selected.end(), fd[i]);
+                selected.erase(j);
 
                 if (lastClicked == fd[i]) {
                     lastClicked = nullptr;
@@ -1452,6 +1456,9 @@ void FileBrowser::applyFilter (const BrowserFilter& filter)
                 selchanged = true;
             }
         }
+        if (selected.empty() || (anchor && std::find(selected.begin(), selected.end(), anchor) == selected.end())) {
+            anchor = nullptr;
+        }
     }
 
     if (selchanged) {
diff --git a/rtgui/thumbbrowserbase.cc b/rtgui/thumbbrowserbase.cc
index 71f9e4a04..20a7d3e44 100644
--- a/rtgui/thumbbrowserbase.cc
+++ b/rtgui/thumbbrowserbase.cc
@@ -172,16 +172,18 @@ void ThumbBrowserBase::selectSingle (ThumbBrowserEntryBase* clicked)
 
 void ThumbBrowserBase::selectRange (ThumbBrowserEntryBase* clicked, bool additional)
 {
-    if (selected.empty() && !anchor) {
-        addToSelection(clicked, selected);
+    if (!anchor) {
         anchor = clicked;
-        return;
+        if (selected.empty()) {
+            addToSelection(clicked, selected);
+            return;
+        }
     }
 
     if (!additional || !lastClicked) {
         // Extend the current range w.r.t to first selected entry.
         ThumbIterator back = std::find(fd.begin(), fd.end(), clicked);
-        ThumbIterator front = std::find(fd.begin(), fd.end(), anchor);
+        ThumbIterator front = anchor == clicked ? back : std::find(fd.begin(), fd.end(), anchor);
 
         if (front > back) {
             std::swap(front, back);
@@ -195,7 +197,7 @@ void ThumbBrowserBase::selectRange (ThumbBrowserEntryBase* clicked, bool additio
     } else {
         // Add an additional range w.r.t. the last clicked entry.
         ThumbIterator last = std::find(fd.begin(), fd.end(), lastClicked);
-        ThumbIterator current = std::find (fd.begin(), fd.end(), clicked);
+        ThumbIterator current = std::find(fd.begin(), fd.end(), clicked);
 
         if (last > current) {
             std::swap(last, current);
@@ -209,12 +211,12 @@ void ThumbBrowserBase::selectRange (ThumbBrowserEntryBase* clicked, bool additio
 
 void ThumbBrowserBase::selectSet (ThumbBrowserEntryBase* clicked)
 {
-    const ThumbIterator iterator = std::find (selected.begin (), selected.end (), clicked);
+    const ThumbIterator iterator = std::find(selected.begin(), selected.end(), clicked);
 
-    if (iterator != selected.end ()) {
-        removeFromSelection (iterator, selected);
+    if (iterator != selected.end()) {
+        removeFromSelection(iterator, selected);
     } else {
-        addToSelection (clicked, selected);
+        addToSelection(clicked, selected);
     }
     anchor = clicked;
 }