From 8e00de3d5fe5e4de45398b323a69eae49b56cf41 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Fri, 23 Feb 2024 10:24:14 +0100
Subject: [PATCH 1/2] facets always use unordered factors

---
 R/facet-grid-.R | 4 ++--
 R/facet-wrap.R  | 4 ++--
 R/utilities.R   | 6 ++++++
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/R/facet-grid-.R b/R/facet-grid-.R
index 839c9ba839..89877fc055 100644
--- a/R/facet-grid-.R
+++ b/R/facet-grid-.R
@@ -323,9 +323,9 @@ FacetGrid <- ggproto("FacetGrid", Facet,
       # Special case of no faceting
       data$PANEL <- NO_PANEL
     } else {
-      facet_vals[] <- lapply(facet_vals[], as.factor)
+      facet_vals[] <- lapply(facet_vals[], as_unordered_factor)
       facet_vals[] <- lapply(facet_vals[], addNA, ifany = TRUE)
-      layout[] <- lapply(layout[], as.factor)
+      layout[] <- lapply(layout[], as_unordered_factor)
 
       keys <- join_keys(facet_vals, layout, by = vars)
 
diff --git a/R/facet-wrap.R b/R/facet-wrap.R
index 9aa488179f..1c522d6fe8 100644
--- a/R/facet-wrap.R
+++ b/R/facet-wrap.R
@@ -226,8 +226,8 @@ FacetWrap <- ggproto("FacetWrap", Facet,
     }
 
     facet_vals <- eval_facets(vars, data, params$.possible_columns)
-    facet_vals[] <- lapply(facet_vals[], as.factor)
-    layout[] <- lapply(layout[], as.factor)
+    facet_vals[] <- lapply(facet_vals[], as_unordered_factor)
+    layout[] <- lapply(layout[], as_unordered_factor)
 
     missing_facets <- setdiff(names(vars), names(facet_vals))
     if (length(missing_facets) > 0) {
diff --git a/R/utilities.R b/R/utilities.R
index 83037d475c..9f9133a0b5 100644
--- a/R/utilities.R
+++ b/R/utilities.R
@@ -811,3 +811,9 @@ deprecate_warn0 <- function(..., user_env = NULL) {
   user_env <- user_env %||% getOption("ggplot2_plot_env") %||% caller_env(2)
   lifecycle::deprecate_warn(..., user_env = user_env)
 }
+
+as_unordered_factor <- function(x) {
+  x <- as.factor(x)
+  class(x) <- setdiff(class(x), "ordered")
+  x
+}

From 292b221cba1cc8947efe57104ab9b02250a826a5 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Fri, 23 Feb 2024 11:30:16 +0100
Subject: [PATCH 2/2] add news bullet

---
 NEWS.md | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/NEWS.md b/NEWS.md
index e6f6dca449..8e1775e861 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,8 @@
 # ggplot2 (development version)
 
+* When facets coerce the faceting variables to factors, the 'ordered' class
+  is dropped (@teunbrand, #5666).
+
 # ggplot2 3.5.0
 
 This is a minor release that turned out quite beefy. It is focused on