Buggy warning message "Record/Alias name '...' should not contain non-printable ...

[Dirk Zimoch]

There are multiple bugs in dbRecordNameValidate() (modules/database/src/ioc/dbStatic/dbLexRoutines.c).

/* any character restrictions */
char c = *pos;
[...]
if(c < ' ') {
  errlogPrintf("Warning: Record/Alias name '%s' should not contain non-printable 0x%02u\n",
                         name, (unsigned)c);
}

1. The check for non-printable characters: if(c < ' ') does not consider implementations where char is signed. Characters with the high bit set are considered negative and thus <' '.
2. Printing the character with "0x%02u" prints a decimal number prefixed with 0x which is confusing (not to say wrong).
3. Casting a signed char to unsigned effectively first sign extends the char to int, then re-interprets it as unsigned int, turning a char >0x80 into a number >4294967168.
On an implementation where char is unsigned, the whole casting is pointless anyway.

This results in confusing warnings like:
Warning: Record/Alias name 'Ä' should not contain non-printable 0x4294967235

The function should explicitly use unsigned char c to fix (c < ' '), use "0x%02x" to format c and not cast c.

[mdavidsaver (mdavidsaver)]

The attached patch looks reasonable to me.

I wondered briefly about how "c < ' '" wrt. type promotion. I think this would promote 'c' from 'unsigned char' to 'int', which should work as intended (excluding char in the range 0 -> 32).

[mdavidsaver (mdavidsaver)]

Patch applied as 42d06d6a38fd08d49daa28e782525393b5c8d82c