From c87a06238e4ad5d3225b0847018a9967a4ea6b74 Mon Sep 17 00:00:00 2001
From: Eric Ihli <eric.ihli@shopify.com>
Date: Tue, 25 Apr 2023 12:33:06 -0700
Subject: [PATCH] Fix scanner to ignore trailing tabs

---
 lib/yaml/scanner.py          | 10 ++++++++++
 tests/data/trailing-tab.code |  1 +
 tests/data/trailing-tab.data |  2 ++
 3 files changed, 13 insertions(+)
 create mode 100644 tests/data/trailing-tab.code
 create mode 100644 tests/data/trailing-tab.data

diff --git a/lib/yaml/scanner.py b/lib/yaml/scanner.py
index de925b07..35621ea5 100644
--- a/lib/yaml/scanner.py
+++ b/lib/yaml/scanner.py
@@ -749,6 +749,14 @@ def check_plain(self):
 
     # Scanners.
 
+    def scan_past_tabs_to_newline(self):
+        i = 0
+        while self.peek(i) in ' \t':
+            i += 1
+        if self.peek(i) in '\0\r\n\x86\u2028\u2029':
+            self.forward(i)
+
+
     def scan_to_next_token(self):
         # We ignore spaces, line breaks and comments.
         # If we find a line break in the block context, we set the flag
@@ -775,6 +783,8 @@ def scan_to_next_token(self):
         while not found:
             while self.peek() == ' ':
                 self.forward()
+            if self.peek() == '\t':
+                self.scan_past_tabs_to_newline()
             if self.peek() == '#':
                 while self.peek() not in '\0\r\n\x85\u2028\u2029':
                     self.forward()
diff --git a/tests/data/trailing-tab.code b/tests/data/trailing-tab.code
new file mode 100644
index 00000000..44bcba58
--- /dev/null
+++ b/tests/data/trailing-tab.code
@@ -0,0 +1 @@
+{"foo": ["bar"]}
diff --git a/tests/data/trailing-tab.data b/tests/data/trailing-tab.data
new file mode 100644
index 00000000..6337bc97
--- /dev/null
+++ b/tests/data/trailing-tab.data
@@ -0,0 +1,2 @@
+foo:
+  - bar