Fix bug with empty strings in repeated string callbacks.

Fix suggested by Henrik Carlgren. Added also unit test for the bug.

Update issue 73
Status: FixedInGit

pb_decode.c

@@ -430,11 +430,11 @@ static bool checkreturn decode_callback_field(pb_istream_t *stream, pb_wire_type
         if (!pb_make_string_substream(stream, &substream))
             return false;
         
-        while (substream.bytes_left)
+        do
         {
             if (!pCallback->funcs.decode(&substream, iter->pos, arg))
                 PB_RETURN_ERROR(stream, "callback failed");
-        }
+        } while (substream.bytes_left);
         
         pb_close_string_substream(stream, &substream);
         return true;

tests/callbacks.proto

@@ -11,5 +11,6 @@ message TestMessage {
     repeated fixed32 fixed32value = 3;
     repeated fixed64 fixed64value = 4;
     optional SubMessage submsg = 5;
+    repeated string repeatedstring = 6;
 }
 

tests/test_decode_callbacks.c

@@ -83,6 +83,8 @@ int main()
     testmessage.fixed32value.arg = "fixed32value: %ld\n";
     testmessage.fixed64value.funcs.decode = &print_fixed64;
     testmessage.fixed64value.arg = "fixed64value: %lld\n";
+    testmessage.repeatedstring.funcs.decode = &print_string;
+    testmessage.repeatedstring.arg = "repeatedstring: \"%s\"\n";
     
     if (!pb_decode(&stream, TestMessage_fields, &testmessage))
         return 1;

tests/test_encode_callbacks.c

@@ -41,6 +41,22 @@ bool encode_fixed64(pb_ostream_t *stream, const pb_field_t *field, void * const
     return pb_encode_fixed64(stream, &value);
 }
 
+bool encode_repeatedstring(pb_ostream_t *stream, const pb_field_t *field, void * const *arg)
+{
+    char *str[4] = {"Hello world!", "", "Test", "Test2"};
+    int i;
+    
+    for (i = 0; i < 4; i++)
+    {
+        if (!pb_encode_tag_for_field(stream, field))
+            return false;
+        
+        if (!pb_encode_string(stream, (uint8_t*)str[i], strlen(str[i])))
+            return false;
+    }
+    return true;
+}
+
 int main()
 {
     uint8_t buffer[1024];
@@ -58,6 +74,8 @@ int main()
     testmessage.submsg.fixed32value.funcs.encode = &encode_fixed32;
     testmessage.submsg.fixed64value.funcs.encode = &encode_fixed64;
 
+    testmessage.repeatedstring.funcs.encode = &encode_repeatedstring;
+    
     if (!pb_encode(&stream, TestMessage_fields, &testmessage))
         return 1;