Fixed bug #20710.

This bug occurs when error message length exceeds allowed limit: my_error()
function outputs "%s" sequences instead of long string arguments.

Formats like %-.64s are very common in errmsg.txt files, however my_error()
function simply ignores precision of those formats.

1 files changed, 13 insertions, 0 deletions

diff --git a/mysys/my_error.c b/mysys/my_error.c
index 8a377f63c7e..0f8ffb7c05f 100644
--- a/mysys/my_error.c
+++ b/mysys/my_error.c
@@ -82,6 +82,11 @@ int my_error(int nr,myf MyFlags, ...)
         If "%.*u" or "%.*d" are encountered, the precision number is read
         from the variable argument list but its value is ignored.
       */
+      if (*tpos == '-')
+      {
+        tpos++;
+        olen--;
+      }
       prec_supplied= 0;
       if (*tpos== '.')
       {
@@ -94,6 +99,14 @@ int my_error(int nr,myf MyFlags, ...)
           prec_chars= va_arg(ap, int); /* get length parameter */
           prec_supplied= 1;
         }
+        else
+        {
+          for (prec_chars= 0; my_isdigit(&my_charset_latin1, *tpos); tpos++, olen--)
+          {
+            prec_supplied= 1;
+            prec_chars= prec_chars * 10 + *tpos - '0';
+          }
+        }
       }
 
       if (!prec_supplied)