From a8cecb5c64141e108f40e2572d34c70b512609d9 Mon Sep 17 00:00:00 2001
From: Cory McWilliams <cory@unprompted.com>
Date: Wed, 1 Feb 2023 03:15:22 +0000
Subject: [PATCH] Fix trace producing invalid JSON.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4159 ed5197a5-7fde-0310-b194-c3ffbd925b24
---
 src/trace.c | 73 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 39 insertions(+), 34 deletions(-)

diff --git a/src/trace.c b/src/trace.c
index 70b209de..77a0e91b 100644
--- a/src/trace.c
+++ b/src/trace.c
@@ -108,6 +108,43 @@ void tf_trace_counter(tf_trace_t* trace, const char* name, int argc, const char*
 	trace->callback(trace, line, p, trace->user_data);
 }
 
+static int _tf_trace_escape_name(char* out, size_t out_size, const char* name)
+{
+	int p = 0;
+	for (const char* c = name; *c && (size_t)p < out_size; c++)
+	{
+		switch (*c)
+		{
+		case '"':
+		case '\\':
+			out[p++] = '\\';
+			if ((size_t)p + 1 < out_size)
+			{
+				out[p++] = *c;
+			}
+			break;
+		case '\t':
+			out[p++] = '\\';
+			if ((size_t)p + 1 < out_size)
+			{
+				out[p++] = 't';
+			}
+			break;
+		case '\n':
+			out[p++] = '\\';
+			if ((size_t)p + 1 < out_size)
+			{
+				out[p++] = 'n';
+			}
+			break;
+		default:
+			out[p++] = *c;
+			break;
+		}
+	}
+	return p;
+}
+
 void tf_trace_begin(tf_trace_t* trace, const char* name)
 {
 	if (!trace)
@@ -131,23 +168,7 @@ void tf_trace_begin(tf_trace_t* trace, const char* name)
 
 	char line[1024];
 	int p = snprintf(line, sizeof(line), "{\"ph\": \"B\", \"pid\": %d, \"tid\": 0, \"ts\": %" PRId64 ", \"name\": \"", getpid(), _trace_ts());
-	for (const char* c = name; *c && p < (int)sizeof(line); c++)
-	{
-		switch (*c)
-		{
-		case '"':
-		case '\\':
-			line[p++] = '\\';
-			if (p < (int)sizeof(line))
-			{
-				line[p++] = *c;
-			}
-			break;
-		default:
-			line[p++] = *c;
-			break;
-		}
-	}
+	p += _tf_trace_escape_name(line + p, sizeof(line) - p, name);
 	p += snprintf(line + p, sizeof(line) - p, "\"},");
 	trace->callback(trace, line, p, trace->user_data);
 }
@@ -177,23 +198,7 @@ void tf_trace_end(tf_trace_t* trace)
 
 	char line[1024];
 	int p = snprintf(line, sizeof(line), "{\"ph\": \"E\", \"pid\": %d, \"tid\": 0, \"ts\": %" PRId64 ", \"name\": \"", getpid(), _trace_ts());
-	for (const char* c = name; *c && p < (int)sizeof(line); c++)
-	{
-		switch (*c)
-		{
-		case '"':
-		case '\\':
-			line[p++] = '\\';
-			if (p < (int)sizeof(line))
-			{
-				line[p++] = *c;
-			}
-			break;
-		default:
-			line[p++] = *c;
-			break;
-		}
-	}
+	p += _tf_trace_escape_name(line + p, sizeof(line) - p, name);
 	p += snprintf(line + p, sizeof(line) - p,  "\"},");
 	trace->callback(trace, line, p, trace->user_data);
 }