<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/79787>79787</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [Flang] Formatted READ, after BN edit descriptor, of numeric field with only '.' non-blanks does not signal error condition (IOSTAT, ERR)
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            bug,
            flang
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          kiranktp
      </td>
    </tr>
</table>

<pre>
    Consider below reproducer:

$ cat -n repro.F90
     1  Program test_BN
     2    Character(6) :: s
     3    Real :: x
     4    Integer :: stat
     5    s = ' .  '
     6    Read(s,1,iostat=stat) x  ! no digits present, error condition
     7    Print '(F4.2,I6)',x,stat
     8    Read(s,2,iostat=stat,BLANK='NULL') x
     9    Print '(F4.2,I6)',x,stat
    10  1 Format(BN,F12.3)
    11  2 Format(F12.3)
    12  End Program test_BN

A BN edit descriptor, or a BLANK='NULL' specifier in a READ statement, should result in an error condition when the F/E/D/EN/ES field consists of the decimal point alone. The words in the Standard are "The input field consists of an optional sign, followed by a string of one or more digits optionally containing a decimal point, including any blanks interpreted as zeros", not allowing for the possibility of decimal point alone.

llvm-flang, gcc, intel do not signal error.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJycVE1v4zYQ_TX0ZRBBGn9IOvjgyBGwaOAukvRcUOJIYkOTAknVcX99MbKz603SS3UYApo3X-8NKUPQvSXaivW9WO8XcoqD89tX7aV9jeOiceq8rZwNWpGHhow7gafROzW15MVyJ9K9SN8trqCVEe7sBZPUZXrxAH8ZwHfvei-PECnEP-8PN05kUw3SyzaSF1hsBJbABZY7CDfAJZsnkubd-XbjXLH5ZiP15H8ERxlvIGs2AcRyDwJzSICPG__mml8JLILAKhNYaTcnWe7nA0t446gMrAOlex0DjJ4C2SiwAvLeeWidVTpqZ29S52y-e23jXBOLepWgwOobzzr_qd4EVh8aLj40hJ8bqu4fd4ffxHIvMD_88fg45yp_Yab8P7WzlFWrnT9yleL-ILCqM0yWHPMTlbF8P1BfABDgwaqv1b_YHdwfgJSOoCi0Xo_ReSbTeZDweToII7W60-RBW5Dw9LDbz0LT8apCGNxkFHgKk4kzyH5UBk4DWYgDQS2wfhBY7_k8sHmGTpNRDA46xACum5GKWn2UBkbHTErjLCXwMhCcnFeB6zDqOUqrpFcgPYFAZIC24xRBPNRiV4ki-5hcWnAjdyUN8JXkGTpnjDuRguYMEkL02vaMdZaYmKPz9L5_77HmzFmj1Jax8td-Oae2rZnU7LRnaIy0r9x2JD96iqRABviHvAsCeT3AOh7TuBOHdM7P840uBN1oo-OZ-_mKlFtxjfn7eNcZaXvO2LftpZFIBpSbK_DE0lwEShZqu1TlspQL2mZ5ulmn-WazWQxbLDdrVbSkurVs11mWd0UqZdYWedmpVVMs9BZTXKUZlul6vcJNItNV2ahl3mDR5a3aiFVKR6lNwi0lzvcLHcJE27zMi3xhZEMmzE8hYjP1FwoE4rV35BfSb-dxmqkPYpUa1u9ntqijmd_Seo5Y76_XgonlHeXBZRfJ_9e6d2CnI3ndXvfvpOMAzpoz39qEN986e3eVTTkKn-i72W-Bxbffn192L5z64elJYLmYvNkOMY6BX0fkxe91HKYmad1RYM2TXI-70bu_qI0C65mkILCeefo3AAD__yRg4fI">