From 21721990cc658235b5dd95a9280f3f1ea2b8b6f0 Mon Sep 17 00:00:00 2001
From: Nate Moore <nate@astro.build>
Date: Thu, 21 Dec 2023 14:04:52 -0600
Subject: [PATCH 1/3] fix: edge case that caused strange panic error

---
 .changeset/calm-parents-tell.md | 5 +++++
 internal/token.go               | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/calm-parents-tell.md

diff --git a/.changeset/calm-parents-tell.md b/.changeset/calm-parents-tell.md
new file mode 100644
index 000000000..67af42491
--- /dev/null
+++ b/.changeset/calm-parents-tell.md
@@ -0,0 +1,5 @@
+---
+'@astrojs/compiler': patch
+---
+
+Fixes an edge case that caused a difficult-to-reproduce panic
diff --git a/internal/token.go b/internal/token.go
index afae341bc..6c1ec6b86 100644
--- a/internal/token.go
+++ b/internal/token.go
@@ -1248,12 +1248,12 @@ func (z *Tokenizer) readUnclosedTag() bool {
 	var close int
 	if z.fm == FrontmatterOpen {
 		close = strings.Index(string(buf), "---")
-		if close != -1 {
+		if close != -1 && len(buf) < close {
 			buf = buf[0:close]
 		}
 	}
 	close = bytes.Index(buf, []byte{'>'})
-	if close != -1 {
+	if close != -1 && len(buf) < close {
 		buf = buf[0:close]
 	}
 	if close == -1 {

From 091e3652355c8056cb53de0b1f796a7ff2aba6bf Mon Sep 17 00:00:00 2001
From: Nate Moore <nate@astro.build>
Date: Thu, 21 Dec 2023 14:44:44 -0600
Subject: [PATCH 2/3] fix: bail out of readUnclosedTag early

---
 internal/token.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/internal/token.go b/internal/token.go
index 6c1ec6b86..5a58e1f79 100644
--- a/internal/token.go
+++ b/internal/token.go
@@ -1251,10 +1251,11 @@ func (z *Tokenizer) readUnclosedTag() bool {
 		if close != -1 && len(buf) < close {
 			buf = buf[0:close]
 		}
-	}
-	close = bytes.Index(buf, []byte{'>'})
-	if close != -1 && len(buf) < close {
-		buf = buf[0:close]
+	} else {
+		close = bytes.Index(buf, []byte{'>'})
+		if close != -1 && len(buf) < close {
+			buf = buf[0:close]
+		}
 	}
 	if close == -1 {
 		// We can't find a closing tag...

From 624bbe57340005ec52c329c79cafee3420cb1ebc Mon Sep 17 00:00:00 2001
From: Nate Moore <nate@astro.build>
Date: Thu, 21 Dec 2023 14:52:29 -0600
Subject: [PATCH 3/3] fix: handle strings before elements

---
 internal/token.go | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/internal/token.go b/internal/token.go
index 5a58e1f79..8a0531966 100644
--- a/internal/token.go
+++ b/internal/token.go
@@ -1879,6 +1879,14 @@ frontmatter_loop:
 			return z.tt
 		}
 
+		// handle string
+		if c == '\'' || c == '"' || c == '`' {
+			z.readString(c)
+			z.tt = TextToken
+			z.data.End = z.raw.End
+			return z.tt
+		}
+
 		s := z.buf[z.raw.Start : z.raw.Start+1][0]
 
 		if s == '<' || s == '{' || s == '}' || c == '<' || c == '{' || c == '}' {
@@ -1892,14 +1900,6 @@ frontmatter_loop:
 			}
 		}
 
-		// handle string
-		if c == '\'' || c == '"' || c == '`' {
-			z.readString(c)
-			z.tt = TextToken
-			z.data.End = z.raw.End
-			return z.tt
-		}
-
 		z.dashCount = 0
 		continue frontmatter_loop
 	}