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

@@ -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;
 			}
 		}
 	}

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

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

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