From e88894a1a3688ca154829426579236f87cd518dd Mon Sep 17 00:00:00 2001
From: Lukasz Stafiniak <lukstafi@gmail.com>
Date: Sat, 30 Dec 2023 21:36:06 +0100
Subject: [PATCH] Fixes #28: no misleading uptick for empty tree nodes

---
 src/printbox-text/PrintBox_text.ml | 10 ++++++++--
 test/test_ann_0_3.expected         |  2 +-
 test/test_blending.expected        | 21 ++++++++++++++++-----
 test/test_blending.ml              |  5 ++++-
 4 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/src/printbox-text/PrintBox_text.ml b/src/printbox-text/PrintBox_text.ml
index 8538049..80324ac 100644
--- a/src/printbox-text/PrintBox_text.ml
+++ b/src/printbox-text/PrintBox_text.ml
@@ -623,10 +623,16 @@ end = struct
         assert (Array.length a > 0);
         if (size n).y > 0 && has_border (Pos.move_y pos' ~-1) conn_m.m then
            conn_m.m <- create_or_update ~ct:`Nontree ~bottom:true (Pos.move_y pos' ~-1) conn_m.m;
+        (* To blend-in an empty tree root with a "wall" to the left: *)
+        (* if (size n).y = 0 then
+          conn_m.m <- create_or_update ~ct:`Nontree ~right:true (Pos.move_x pos' ~-1) conn_m.m; *)
         let _ = _array_foldi
             (fun pos' i b ->
-               let s = "└─" in
-               conn_m.m <- create_or_update ~ct:`Tree ~top:true ~right:true pos' conn_m.m;
+               let s = if pos'.y = pos.y then "──" else "└─" in
+               if pos'.y <> pos.y then
+                 conn_m.m <- create_or_update ~ct:`Tree ~top:true ~right:true pos' conn_m.m
+               else
+                 conn_m.m <- create_or_update ~ct:`Tree ~left:true ~right:true pos' conn_m.m;
                conn_m.m <- create_or_update ~ct:`Tree ~left:true ~right:true (Pos.move_x pos' 1) conn_m.m;
                conn_m.m <- create_or_update ~ct:`Tree ~top:true (Pos.move_y pos' 1) conn_m.m;
                if i<Array.length a-1 then (
diff --git a/test/test_ann_0_3.expected b/test/test_ann_0_3.expected
index 3c1a377..6ab59c9 100644
--- a/test/test_ann_0_3.expected
+++ b/test/test_ann_0_3.expected
@@ -14,7 +14,7 @@
 │                 ├──────────────────────────────────────────────────────────────┤
 │                 │Matt                                                          │
 ├─────────────────┼──────────────────────────────────────────────────────────────┤
-│dependencies     │├─mandatory                                                   │
+│dependencies     │┬─mandatory                                                   │
 │                 ││ ├─dune                                                      │
 │                 ││ ├─bytes                                                     │
 │                 ││ ├─uutf                                                      │
diff --git a/test/test_blending.expected b/test/test_blending.expected
index dc62762..0752b8f 100644
--- a/test/test_blending.expected
+++ b/test/test_blending.expected
@@ -6,19 +6,30 @@
 │ └───────┘
 ├─child 2
 ├─┬──────────────────┐
-│ │└─┬────────┐      │
+│ │──┬────────┐      │
 │ │  │header 3│      │
 │ │  ├────────┘      │
 │ │  └─┬──────────┐  │
 │ │    │subchild 3│  │
 │ │    └──────────┘  │
 │ └──────────────────┘
-├─└─┬────────┐
+├───┬────────┐
 │   │header 4│
 │   ├────────┘
 │   └─┬──────────┐
 │     │subchild 4│
 │     └──────────┘
-└─┬───────┐
-  │child 5│
-  └───────┘
+├─┬───────┐
+│ │child 5│
+│ └───────┘
+└─┬──────────────────┐
+  │┌────────┐        │
+  ││header 6│        │
+  │├────────┘        │
+  │└─┬───────┐       │
+  │  │child 6│       │
+  │  ├───────┘       │
+  │  └─┬──────────┐  │
+  │    │subchild 6│  │
+  │    └──────────┘  │
+  └──────────────────┘
diff --git a/test/test_blending.ml b/test/test_blending.ml
index 3f92388..08e2a5d 100644
--- a/test/test_blending.ml
+++ b/test/test_blending.ml
@@ -9,7 +9,10 @@ let b =
     tree empty [
       tree (frame @@ text "header 4") [frame @@ text "subchild 4"]
     ];
-    frame @@ text "child 5"
+    frame @@ text "child 5";
+    frame @@ tree (frame @@ text "header 6") [
+      tree (frame @@ text "child 6") [frame @@ text "subchild 6"]
+    ]
   ]
 
 let () = print_endline @@ PrintBox_text.to_string b