From 7752e4bf3beb85f8213efd4dee9d347e58ecc601 Mon Sep 17 00:00:00 2001
From: Raheman Vaiya <r.vaiya@gmail.com>
Date: Wed, 30 Mar 2022 05:36:55 -0400
Subject: [PATCH] Always use the longest composite layer

Currently composite layers will be activated in the order in which they
are defined which can cause shorter sequences to take precedence over
longer ones. This patch ensures the longest composite sequence always
takes precedence.
---
 src/keyboard.c |  6 +++++-
 t/composite.t  | 21 +++++++++++++++++++++
 t/composite2.t | 25 +++++++++++++++++++++++++
 t/test.conf    |  8 ++++++++
 4 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 t/composite.t
 create mode 100644 t/composite2.t

diff --git a/src/keyboard.c b/src/keyboard.c
index 2a0264a..564796c 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -200,6 +200,7 @@ void kbd_reset(struct keyboard *kbd)
 
 static void lookup_descriptor(struct keyboard *kbd, uint8_t code, uint8_t *layer_mods, struct descriptor *d)
 {
+	size_t max;
 	size_t i;
 	uint8_t active[MAX_LAYERS];
 	struct layer_table *lt = &kbd->layer_table;
@@ -223,6 +224,7 @@ static void lookup_descriptor(struct keyboard *kbd, uint8_t code, uint8_t *layer
 		}
 	}
 
+	max = 0;
 	/* Scan for any composite matches (which take precedence). */
 	for (i = 0; i < lt->nr; i++) {
 		struct layer *layer = &lt->layers[i];
@@ -239,9 +241,11 @@ static void lookup_descriptor(struct keyboard *kbd, uint8_t code, uint8_t *layer
 					match = 0;
 			}
 
-			if (match && layer->keymap[code].op) {
+			if (match && layer->keymap[code].op && (layer->nr_layers > max)) {
 				*layer_mods = mods;
 				*d = layer->keymap[code];
+
+				max = layer->nr_layers;
 			}
 		}
 	}
diff --git a/t/composite.t b/t/composite.t
new file mode 100644
index 0000000..952c177
--- /dev/null
+++ b/t/composite.t
@@ -0,0 +1,21 @@
+control down
+alt down
+h down
+h up
+control up
+alt up
+
+control down
+alt down
+alt up
+control up
+shift down
+h down
+h up
+shift up
+control down
+alt down
+control up
+control down
+alt up
+control up
diff --git a/t/composite2.t b/t/composite2.t
new file mode 100644
index 0000000..6edc1d8
--- /dev/null
+++ b/t/composite2.t
@@ -0,0 +1,25 @@
+control down
+shift down
+alt down
+h down
+h up
+control up
+shift up
+alt up
+
+control down
+shift down
+alt down
+alt up
+control up
+shift up
+left down
+left up
+control down
+shift down
+alt down
+control up
+shift up
+control down
+alt up
+control up
diff --git a/t/test.conf b/t/test.conf
index 321c043..83d730a 100644
--- a/t/test.conf
+++ b/t/test.conf
@@ -73,6 +73,14 @@ s = swap(swapped1)
 1 = swap(tablayer, tab)
 2 = swap(tablayer2, tab)
 
+[myalt+control+shift]
+
+h = left
+
+[myalt+control]
+
+h = H
+
 [swapped1]
 
 a = b