From 74a41951e6b4957415868983ed24338256176457 Mon Sep 17 00:00:00 2001
From: Meghan Denny <hello@nektro.net>
Date: Mon, 8 Jun 2026 01:46:07 -0700
Subject: [PATCH] handle anchor events and fix another crash

---
 ...16058,execs:7921,op:arith8,pos:522,val:+10 | 31 +++++++++++++++++++
 test.zig                                      |  1 +
 yaml.zig                                      |  9 ++++++
 3 files changed, 41 insertions(+)
 create mode 100644 fuzz/crashes/id:000000,sig:06,src:000000,time:16058,execs:7921,op:arith8,pos:522,val:+10

diff --git a/fuzz/crashes/id:000000,sig:06,src:000000,time:16058,execs:7921,op:arith8,pos:522,val:+10 b/fuzz/crashes/id:000000,sig:06,src:000000,time:16058,execs:7921,op:arith8,pos:522,val:+10
new file mode 100644
index 0000000000000000000000000000000000000000..09ca75df0d89db030be89209d8c35c457bcb1794
--- /dev/null
+++ b/fuzz/crashes/id:000000,sig:06,src:000000,time:16058,execs:7921,op:arith8,pos:522,val:+10
@@ -0,0 +1,31 @@
+id: g982zq6e8wsvnmduerpbf8787hu85brugmngn8wf
+name: yaml
+main: yaml.zig
+license: MIT
+description: A Yaml parser built on top of libyaml
+dependencies:
+  - src: git https://github.com/yaml/libyaml tag-0.2.5
+    id: 8mdbh0zuneb0i3hs5jby5je0heem1i6yxusl7c8y8qx68hqc
+    license: MIT
+    c_include_dirs:
+      - include
+    c_source_flags:
+      - -DYAML_VERSION_MAJOR=0
+      - -DYAML_VERSION_MINOR=2
+      - -DYAML_VERSION_PATCH=5
+      - -DYAML_VERSION_STRING="0.2.5"
+      - -DYAML_DECLARE_STATIC=1
+    c_source_files:
+     *- src/api.c
+      - src/dumper.c
+      - src/emitter.c
+      - src/loader.c
+      - src/parser.c
+      - src/reader.c
+      - src/scanner.c
+      - src/writer.c
+
+  - src: git https://github.com/nektro/zig-extras
+
+root_dependencies:
+  - src: git https://github.com/nektro/zig-expect
diff --git a/test.zig b/test.zig
index 048e03cc35ba2d75c068102f3478a0024df44a8e..d1f4d8bee7fdfe1cfc100671f32baeeb0aa329cc 100644
--- a/test.zig
+++ b/test.zig
@@ -24,6 +24,7 @@ test { fuzzCase(@embedFile("./fuzz/crashes/id:000000,sig:06,src:000000,time:6342
 test { fuzzCase(@embedFile("./fuzz/crashes/id:000000,sig:06,src:000000,time:1310,execs:717,op:quick,pos:97")); }
 test { fuzzCase(@embedFile("./fuzz/crashes/id:000000,sig:06,src:000000,time:1399,execs:755,op:quick,pos:149")); }
 test { fuzzCase(@embedFile("./fuzz/crashes/id:000002,sig:06,src:000000,time:12249,execs:9637,op:int8,pos:0,val:+32")); }
+test { fuzzCase(@embedFile("./fuzz/crashes/id:000000,sig:06,src:000000,time:16058,execs:7921,op:arith8,pos:522,val:+10")); }
 // zig fmt: on
 
 fn parseTest(comptime basename: [:0]const u8) !void {
diff --git a/yaml.zig b/yaml.zig
index d33ee6ef83e137855473c774cee1ad49c91d94bb..725fc3d19b2475d5eacdaa990720ed9b07d078f6 100644
--- a/yaml.zig
+++ b/yaml.zig
@@ -39,6 +39,7 @@ pub const Item = union(enum) {
     sequence: Sequence,
     string: [:0]const u8,
     stream: Stream,
+    anchor: [:0]const u8,
 
     pub fn deinit(self: *const Item, alloc: std.mem.Allocator) void {
         switch (self.*) {
@@ -51,6 +52,7 @@ pub const Item = union(enum) {
             },
             .string => |s| alloc.free(s),
             .stream => |s| s.deinit(alloc),
+            .anchor => {},
         }
     }
 
@@ -76,6 +78,9 @@ pub const Item = union(enum) {
             .string => {
                 try writer.print("{s}", .{self.string});
             },
+            .anchor => {
+                //
+            },
         }
         try writer.writeAll("}");
     }
@@ -97,6 +102,7 @@ pub const Value = union(enum) {
     string: [:0]const u8,
     mapping: Mapping,
     sequence: Sequence,
+    anchor: [:0]const u8,
 
     pub fn deinit(self: *const Value, alloc: std.mem.Allocator) void {
         switch (self.*) {
@@ -108,6 +114,7 @@ pub const Value = union(enum) {
                 for (s) |*item| item.deinit(alloc);
                 alloc.free(s);
             },
+            .anchor => {},
         }
     }
 
@@ -268,6 +275,7 @@ fn parse_item(p: *Parser, start: ?Token) Error!Item {
         c.YAML_MAPPING_START_EVENT => Item{ .mapping = try parse_mapping(p) },
         c.YAML_SEQUENCE_START_EVENT => Item{ .sequence = try parse_sequence(p) },
         c.YAML_SCALAR_EVENT => Item{ .string = try get_event_string(tok, p) },
+        c.YAML_ALIAS_EVENT => .{ .anchor = std.mem.sliceTo(tok.data.alias.anchor, 0) },
         else => unreachable,
     };
 }
@@ -344,6 +352,7 @@ fn parse_value(p: *Parser) Error!Value {
         .mapping => |x| Value{ .mapping = x },
         .sequence => |x| Value{ .sequence = x },
         .string => |x| Value{ .string = x },
+        .anchor => |x| Value{ .anchor = x },
         else => unreachable,
     };
 }
-- 
2.54.0