Bug#22807 mysql_upgrade fails when called with a basedir-path containing spaces

- Create space safe strings for system() calls in mysql_upgrade.exe


client/mysql_upgrade.c:
  Bug#22807 mysql_upgrade fails when called with a basedir-path containing spaces
  - Make use of new dynstr_append_os_quoted function to produce a string safe for
  passing to the system() function.                                              
  - Refactor possible source of assertion.
include/my_sys.h:
  Bug#22807 mysql_upgrade fails when called with a basedir-path containing spaces
  - Declare dynstr_append_os_quoted function.
mysys/string.c:
  Bug#22807 mysql_upgrade fails when called with a basedir-path containing spaces
  - Define dynstr_append_os_quoted function.  This function will concatenate any 
  number of strings, escapes any OS quote in the result then surround the whole  
  affair in another set of quotes which is finally appended to specified         
  DYNAMIC_STRING.

1 files changed, 52 insertions, 0 deletions

diff --git a/mysys/string.c b/mysys/string.c
index dfd42d137dd..c5657cd430d 100644
--- a/mysys/string.c
+++ b/mysys/string.c
@@ -116,6 +116,58 @@ my_bool dynstr_append_mem(DYNAMIC_STRING *str, const char *append,
 }
 
 
+/** Concatenates any number of strings, escapes any OS quote in the result then
+ * surround the whole affair in another set of quotes which is finally appended
+ * to specified DYNAMIC_STRING.  This function is especially useful when 
+ * building strings to be executed with the system() function.
+ * @param str Dynamic String which will have addtional strings appended.
+ * @param append String to be appended.
+ * @param ... Optional. Additional string(s) to be appended.
+ *
+ * @note The final argument in the list must be NullS even if no additional
+ * options are passed.
+ *
+ * @return True = Success.
+ */
+my_bool dynstr_append_os_quoted(DYNAMIC_STRING *str, const char *append, ...)
+{
+#ifdef __WIN__
+  char quote_str[]= "\"";
+#else
+  char quote_str[]= "\'";
+#endif /* __WIN__ */
+  my_bool ret= TRUE;
+  va_list dirty_text;
+
+  ret&= dynstr_append(str, quote_str);          /* Leading quote */
+  va_start(dirty_text,append);
+  while (append != NullS)
+  {
+    char *cur_pos=  append;
+    char *next_pos= cur_pos;
+
+    /* Search for quote in each string and replace with escaped quote */
+    while(*(next_pos= strcend(cur_pos, quote_str[0])) != '\0')
+    {
+      char *tmp_buff= my_malloc((next_pos - cur_pos) + 1, MYF(MY_ZEROFILL));
+      strnmov(tmp_buff, cur_pos, (next_pos - cur_pos));
+      ret&= dynstr_append(str, tmp_buff);
+      my_free((gptr)tmp_buff, MYF(0));
+
+      ret&= dynstr_append(str ,"\\");
+      ret&= dynstr_append(str, quote_str);
+      cur_pos= next_pos + 1;
+    }
+    ret&= dynstr_append(str, cur_pos);
+    append= va_arg(dirty_text, char *);
+  }
+  va_end(dirty_text);
+  ret&= dynstr_append(str, quote_str);          /* Trailing quote */
+
+  return ret;
+}
+
+
 void dynstr_free(DYNAMIC_STRING *str)
 {
   if (str->str)