Fix writing long literals with triple quotes

5 files changed, 83 insertions, 4 deletions

diff --git a/NEWS b/NEWS
index 7e40cd29..03636d41 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,9 @@
+serd (0.30.11) unstable;
+
+  * Fix writing long literals with triple quotes
+
+ -- David Robillard <d@drobilla.net>  Mon, 15 Feb 2021 16:34:35 +0000
+
 serd (0.30.10) stable;
 
   * Add fallback configuration if documentation theme is unavailable
diff --git a/src/serd_config.h b/src/serd_config.h
index 349d7124..15508c81 100644
--- a/src/serd_config.h
+++ b/src/serd_config.h
@@ -29,7 +29,7 @@
 #define SERD_CONFIG_H
 
 // Define version unconditionally so a warning will catch a mismatch
-#define SERD_VERSION "0.30.10"
+#define SERD_VERSION "0.30.11"
 
 #if !defined(SERD_NO_DEFAULT_CONFIG)
 
diff --git a/src/writer.c b/src/writer.c
index 82ac5eeb..af2980c5 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -332,8 +332,13 @@ write_text(SerdWriter*    writer,
            const uint8_t* utf8,
            size_t         n_bytes)
 {
-  size_t len = 0;
+  size_t len                  = 0;
+  size_t n_consecutive_quotes = 0;
   for (size_t i = 0; i < n_bytes;) {
+    if (utf8[i] != '"') {
+      n_consecutive_quotes = 0;
+    }
+
     // Fast bulk write for long strings of printable ASCII
     size_t j = i;
     for (; j < n_bytes; ++j) {
@@ -350,6 +355,8 @@ write_text(SerdWriter*    writer,
 
     const uint8_t in = utf8[i++];
     if (ctx == WRITE_LONG_STRING) {
+      n_consecutive_quotes = (in == '\"') ? (n_consecutive_quotes + 1) : 0;
+
       switch (in) {
       case '\\':
         len += sink("\\\\", 2, writer);
@@ -364,7 +371,8 @@ write_text(SerdWriter*    writer,
         len += sink(&in, 1, writer); // Write character as-is
         continue;
       case '\"':
-        if (i == n_bytes) { // '"' at string end
+        if (n_consecutive_quotes >= 3 || i == n_bytes) {
+          // Two quotes in a row, or quote at string end, escape
           len += sink("\\\"", 2, writer);
         } else {
           len += sink(&in, 1, writer);
diff --git a/test/test_writer.c b/test/test_writer.c
new file mode 100644
index 00000000..baaff736
--- /dev/null
+++ b/test/test_writer.c
@@ -0,0 +1,65 @@
+/*
+  Copyright 2011-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#undef NDEBUG
+
+#include "serd/serd.h"
+
+#include <assert.h>
+#include <string.h>
+
+#define USTR(s) ((const uint8_t*)(s))
+
+static void
+test_write_long_literal(void)
+{
+  SerdEnv*    env    = serd_env_new(NULL);
+  SerdChunk   chunk  = {NULL, 0};
+  SerdWriter* writer = serd_writer_new(
+    SERD_TURTLE, (SerdStyle)0, env, NULL, serd_chunk_sink, &chunk);
+
+  assert(writer);
+
+  SerdNode s = serd_node_from_string(SERD_URI, USTR("http://example.org/s"));
+  SerdNode p = serd_node_from_string(SERD_URI, USTR("http://example.org/p"));
+  SerdNode o =
+    serd_node_from_string(SERD_LITERAL, USTR("hello \"\"\"world\"\"\"!"));
+
+  assert(!serd_writer_write_statement(writer, 0, NULL, &s, &p, &o, NULL, NULL));
+
+  serd_writer_free(writer);
+
+  uint8_t* out = serd_chunk_sink_finish(&chunk);
+
+  static const char* const expected =
+    "<http://example.org/s>\n"
+    "\t<http://example.org/p> \"\"\"hello \"\"\\\"world\"\"\\\"!\"\"\" .\n\n";
+
+  assert(!strcmp((char*)out, expected));
+  serd_free(out);
+}
+
+int
+main(void)
+{
+  const char* const path = "serd_test.ttl";
+
+  test_writer(path);
+  test_write_long_literal();
+
+  printf("Success\n");
+  return 0;
+}
diff --git a/wscript b/wscript
index 034bd85e..2a4085b4 100644
--- a/wscript
+++ b/wscript
@@ -11,7 +11,7 @@ from waflib.extras import autowaf
 # major increment <=> incompatible changes
 # minor increment <=> compatible changes (additions)
 # micro increment <=> no interface changes
-SERD_VERSION       = '0.30.10'
+SERD_VERSION       = '0.30.11'
 SERD_MAJOR_VERSION = '0'
 
 # Mandatory waf variables