Fix issues found in fsqlf_format_bytes()

Actual issues were in print_kw() and print_nonkw_text(),
which always wrote to the start of the buffer.
(they have to increment 'start' of the text each time)

lib_fsqlf/formatter/print_keywords.c

@@ -213,8 +213,11 @@ static void print_kw(
             assert(bout->buffer);
             bout->len_alloc = len_realloc;
         }
-        strncpy(bout->buffer, spacing_txt, len_spacing);
-        strncpy(bout->buffer, text, len_text);
+        strncpy(bout->buffer + bout->len_used, spacing_txt, len_spacing);
+        bout->len_used += len_spacing;
+        strncpy(bout->buffer + bout->len_used, text, len_text);
+        bout->len_used += len_text;
+        bout->buffer[bout->len_used] = '\0';
     }
 
     free(spacing_txt);
@@ -267,8 +270,11 @@ static void print_nonkw_text(
             assert(bout->buffer);
             bout->len_alloc = len_realloc;
         }
-        strncpy(bout->buffer, spacing_txt, len_spacing);
-        strncpy(bout->buffer, txtdup, len_text);
+        strncpy(bout->buffer + bout->len_used, spacing_txt, len_spacing);
+        bout->len_used += len_spacing;
+        strncpy(bout->buffer + bout->len_used, txtdup, len_text);
+        bout->len_used += len_text;
+        bout->buffer[bout->len_used] = '\0';
     }
 
     free(txtdup);

makefile

@@ -105,7 +105,13 @@ $(EXEC_CLI): $(COBJ) $(LIBNAME)
 	$(CC) $(CFLAGS)  $(COBJ)  -L. -lfsqlf  -Wl,-rpath,.  -o $@
 	# strip $@
 
+testcases/test_fsqlf_format_bytes: testcases/test_fsqlf_format_bytes.o
+	$(CC) $(CFLAGS)  $<  -L. -lfsqlf  -Wl,-rpath,.  -o $@
 
+testcases/test_fsqlf_format_bytes.o: testcases/test_fsqlf_format_bytes.c
+	$(CC) $(CFLAGS)  -c $<  -o $@
+
+newtest: testcases/test_fsqlf_format_bytes
 
 #
 # BUILD GUI