From 93a7395c1928752b44f35f34d7dd633cb58a7253 Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Sun, 4 Nov 2018 15:25:30 -0800
Subject: [PATCH] Fix invalid dot syntax when token names contain quotes or
 newlines

---
 src/runtime/subtree.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/runtime/subtree.c b/src/runtime/subtree.c
index 13af2ba2..6415a176 100644
--- a/src/runtime/subtree.c
+++ b/src/runtime/subtree.c
@@ -766,6 +766,18 @@ static size_t ts_subtree__write_char_to_string(char *s, size_t n, int32_t c) {
     return snprintf(s, n, "%d", c);
 }
 
+static void ts_subtree__write_dot_string(FILE *f, const char *string) {
+  for (const char *c = string; *c; c++) {
+    if (*c == '"') {
+      fputs("\\\"", f);
+    } else if (*c == '\n') {
+      fputs("\\n", f);
+    } else {
+      fputc(*c, f);
+    }
+  }
+}
+
 static size_t ts_subtree__write_to_string(Subtree self, char *string, size_t limit,
                                           const TSLanguage *language, bool is_root,
                                           bool include_all, TSSymbol alias_symbol,
@@ -845,10 +857,9 @@ void ts_subtree__print_dot_graph(const Subtree *self, uint32_t start_offset,
   TSSymbol subtree_symbol = ts_subtree_symbol(*self);
   TSSymbol symbol = alias_symbol ? alias_symbol : subtree_symbol;
   uint32_t end_offset = start_offset + ts_subtree_total_bytes(*self);
-  fprintf(
-    f, "tree_%p [label=\"%s\"",
-    self, ts_language_symbol_name(language, symbol)
-  );
+  fprintf(f, "tree_%p [label=\"", self);
+  ts_subtree__write_dot_string(f, ts_language_symbol_name(language, symbol));
+  fprintf(f, "\"");
 
   if (ts_subtree_child_count(*self) == 0) fprintf(f, ", shape=plaintext");
   if (ts_subtree_extra(*self)) fprintf(f, ", fontcolor=gray");