unit test for dynstr_append_os_quoted()

and a trivial cleanup to avoid manually-specified lengths

unittest/mysys/CMakeLists.txt

@@ -14,7 +14,7 @@
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 
 MY_ADD_TESTS(bitmap base64 my_vsnprintf my_atomic my_rdtsc lf my_malloc
-             my_getopt
+             my_getopt dynstring
              LINK_LIBRARIES mysys)
 
 IF(WIN32)

unittest/mysys/dynstring-t.c

@@ -0,0 +1,74 @@
+/* Copyright (c) 2016, MariaDB
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
+
+//#include <my_global.h>
+#include <m_string.h>
+#include <my_sys.h>
+#include <tap.h>
+
+DYNAMIC_STRING str1;
+
+static void check(const char *res)
+{
+  ok(strcmp(str1.str, res) == 0, "strcmp: %s", str1.str);
+  str1.length= 0;
+}
+
+int main(void)
+{
+  plan(23);
+
+  IF_WIN(skip_all("Test of POSIX shell escaping rules, not for CMD.EXE\n"), );
+
+  ok(init_dynamic_string(&str1, NULL, 0, 32) == 0, "init");
+
+  ok(dynstr_append_os_quoted(&str1, "test1", NULL) == 0, "append");
+  check("'test1'");
+
+  ok(dynstr_append_os_quoted(&str1, "con", "cat", NULL) == 0, "append");
+  check("'concat'");
+
+  ok(dynstr_append_os_quoted(&str1, "", NULL) == 0, "append");
+  check("''");
+
+  ok(dynstr_append_os_quoted(&str1, "space inside", NULL) == 0, "append");
+  check("'space inside'");
+
+  ok(dynstr_append_os_quoted(&str1, "single'quote", NULL) == 0, "append");
+  check("'single\\'quote'");
+
+  ok(dynstr_append_os_quoted(&str1, "many'single'quotes", NULL) == 0, "append");
+  check("'many\\'single\\'quotes'");
+
+  ok(dynstr_append_os_quoted(&str1, "'single quoted'", NULL) == 0, "append");
+  check("'\\'single quoted\\''");
+
+  ok(dynstr_append_os_quoted(&str1, "double\"quote", NULL) == 0, "append");
+  check("'double\"quote'");
+
+  ok(dynstr_append_os_quoted(&str1, "mixed\"single'and\"double'quotes", NULL) == 0, "append");
+  check("'mixed\"single\\'and\"double\\'quotes'");
+
+  ok(dynstr_append_os_quoted(&str1, "back\\space", NULL) == 0, "append");
+  check("'back\\space'");
+
+  ok(dynstr_append_os_quoted(&str1, "backspace\\'and\\\"quote", NULL) == 0, "append");
+  check("'backspace\\\\'and\\\"quote'");
+
+  dynstr_free(&str1);
+
+  return exit_status();
+}
+