WIP: Write invalid characters in URIs with percent encoding

2 files changed, 11 insertions, 5 deletions

diff --git a/src/writer.c b/src/writer.c
index 8632b0b5..38a64459 100644
--- a/src/writer.c
+++ b/src/writer.c
@@ -220,8 +220,8 @@ write_character(SerdWriter* writer, const uint8_t* utf8, size_t* size)
   switch (*size) {
   case 0:
     serd_world_errorf(
-      writer->world, SERD_ERR_BAD_ARG, "invalid UTF-8: %X\n", utf8[0]);
-    return sink(replacement_char, sizeof(replacement_char), writer);
+      writer->world, SERD_ERR_BAD_ARG, "invalid UTF-8 start: %X\n", utf8[0]);
+    return 0;
   case 1:
     snprintf(escape, sizeof(escape), "\\u%04X", utf8[0]);
     return sink(escape, 6, writer);
@@ -286,8 +286,11 @@ write_uri(SerdWriter* writer, const char* utf8, size_t n_bytes)
     len += write_character(writer, (const uint8_t*)utf8 + i, &size);
     i += size;
     if (size == 0) {
-      // Corrupt input, scan to start of next character
-      for (++i; i < n_bytes && (utf8[i] & 0x80); ++i) {
+      // Corrupt input, write percent-encoded byts and scan to next start
+      char escape[4] = {0, 0, 0, 0};
+      for (; i < n_bytes && (utf8[i] & 0x80); ++i) {
+        snprintf(escape, sizeof(escape), "%%%02X", (uint8_t)utf8[i]);
+        len += sink(escape, 3, writer);
       }
     }
   }
@@ -457,7 +460,8 @@ write_text(SerdWriter* writer,
     len += write_character(writer, (const uint8_t*)utf8 + i - 1, &size);
 
     if (size == 0) {
-      // Corrupt input, scan to start of next character
+      // Corrupt input, write repacement character and scan to the next start
+      len += sink(replacement_char, sizeof(replacement_char), writer);
       for (; i < n_bytes && (utf8[i] & 0x80); ++i) {
       }
     } else {
diff --git a/test/test_reader_writer.c b/test/test_reader_writer.c
index f526a68c..8cbce04e 100644
--- a/test/test_reader_writer.c
+++ b/test/test_reader_writer.c
@@ -40,7 +40,9 @@ static size_t
 eof_test_read(void* buf, size_t size, size_t nmemb, void* stream)
 {
   assert(size == 1);
+  assert(nmemb == 1);
   (void)size;
+  (void)nmemb;
 
   static const char* const string = "_:s1 <http://example.org/p> _:o1 .\n"
                                     "_:s2 <http://example.org/p> _:o2 .\n";