From 953f1aeb296b741316e438f706ac6317b875e0e4 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 30 Aug 2022 10:02:40 -0700
Subject: [PATCH] pkg/harfbuzz: fixing some APIs

---
 pkg/harfbuzz/common.zig | 11 ++++++++---
 pkg/harfbuzz/shape.zig  | 12 +++++++++++-
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/pkg/harfbuzz/common.zig b/pkg/harfbuzz/common.zig
index 84b4d000f..a4cff17b5 100644
--- a/pkg/harfbuzz/common.zig
+++ b/pkg/harfbuzz/common.zig
@@ -228,13 +228,13 @@ pub const Feature = extern struct {
     end: c_uint,
 
     pub fn fromString(str: []const u8) ?Feature {
-        var f: Feature = undefined;
+        var f: c.hb_feature_t = undefined;
         return if (c.hb_feature_from_string(
             str.ptr,
             @intCast(c_int, str.len),
             &f,
-        ) > 1)
-            f
+        ) > 0)
+            @bitCast(Feature, f)
         else
             null;
     }
@@ -243,3 +243,8 @@ pub const Feature = extern struct {
         c.hb_feature_to_string(self, buf.ptr, @intCast(c_uint, buf.len));
     }
 };
+
+test "feature from string" {
+    const testing = std.testing;
+    try testing.expect(Feature.fromString("dlig") != null);
+}
diff --git a/pkg/harfbuzz/shape.zig b/pkg/harfbuzz/shape.zig
index 260fbc85d..3567c8b11 100644
--- a/pkg/harfbuzz/shape.zig
+++ b/pkg/harfbuzz/shape.zig
@@ -10,10 +10,20 @@ const Feature = @import("common.zig").Feature;
 /// but overlapping ranges the value of the feature with the higher index
 /// takes precedence.
 pub fn shape(font: Font, buf: Buffer, features: ?[]const Feature) void {
+    const hb_feats: [*c]const c.hb_feature_t = feats: {
+        if (features) |fs| {
+            if (fs.len > 0) {
+                break :feats @ptrCast([*]const c.hb_feature_t, fs.ptr);
+            }
+        }
+
+        break :feats null;
+    };
+
     c.hb_shape(
         font.handle,
         buf.handle,
-        if (features) |f| @ptrCast([*]const c.hb_feature_t, f.ptr) else null,
+        hb_feats,
         if (features) |f| @intCast(c_uint, f.len) else 0,
     );
 }