Fix potential memory leaks when a write is aborted

Also clean up and simplify writer context management in general.

1 files changed, 49 insertions, 0 deletions

diff --git a/test/test_writer.c b/test/test_writer.c
index c1a5f468..356dbfcb 100644
--- a/test/test_writer.c
+++ b/test/test_writer.c
@@ -7,6 +7,7 @@
 
 #include <assert.h>
 #include <stdint.h>
+#include <stdio.h>
 #include <string.h>
 
 #define USTR(s) ((const uint8_t*)(s))
@@ -41,10 +42,58 @@ test_write_long_literal(void)
   serd_free(out);
 }
 
+static size_t
+null_sink(const void* const buf, const size_t len, void* const stream)
+{
+  (void)buf;
+  (void)stream;
+
+  return len;
+}
+
+static void
+test_writer_cleanup(void)
+{
+  SerdStatus  st  = SERD_SUCCESS;
+  SerdEnv*    env = serd_env_new(NULL);
+  SerdWriter* writer =
+    serd_writer_new(SERD_TURTLE, (SerdStyle)0U, env, NULL, null_sink, NULL);
+
+  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_BLANK, USTR("http://example.org/o"));
+
+  st = serd_writer_write_statement(
+    writer, SERD_ANON_O_BEGIN, NULL, &s, &p, &o, NULL, NULL);
+
+  assert(!st);
+
+  // Write the start of several nested anonymous objects
+  for (unsigned i = 0U; !st && i < 8U; ++i) {
+    char buf[12] = {0};
+    snprintf(buf, sizeof(buf), "b%u", i);
+
+    SerdNode next_o = serd_node_from_string(SERD_BLANK, USTR(buf));
+
+    st = serd_writer_write_statement(
+      writer, SERD_ANON_O_BEGIN, NULL, &o, &p, &next_o, NULL, NULL);
+
+    o = next_o;
+  }
+
+  // Finish writing without terminating nodes
+  assert(!(st = serd_writer_finish(writer)));
+
+  // Free (which could leak if the writer doesn't clean up the stack properly)
+  serd_writer_free(writer);
+  serd_env_free(env);
+}
+
 int
 main(void)
 {
   test_write_long_literal();
+  test_writer_cleanup();
 
   return 0;
 }