bug#34858: indent-relative called with prefix calls tab-to-tab-stop

[Alex <agrambot@gmail.com>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Alex Branham <alex.branham@gmail.com>
>> Date: Thu, 14 Mar 2019 10:35:13 -0500
>> 
>> If the previous nonblank line has no indent points beyond the
>> column point starts at, then `tab-to-tab-stop' is done, if both
>> FIRST-ONLY and UNINDENTED-OK are nil, otherwise nothing is done
>> in this case.
>> 
>> Yet in a buffer like this:
>> 
>> foo
>> 
>> with point at the beginning of line, C-u M-x indent-relative results in:
>> 
>>         test
>> 
>> I'm happy to submit a patch fixing this, but should it update the
>> documentation to match what happens or should it update the code to
>> match the documentation?
>
> I think this is a documentation bug, as it doesn't describe the
> special case of "no previous nonblank line".

I believe that the case of "no previous nonblank line" could be
considered as there being a single indent point at column 0, so if
FIRST-ONLY is non-nil, then `tab-to-tab-stop' shouldn't be called. How
about the following patch instead?

diff --git a/lisp/indent.el b/lisp/indent.el
index 34757a43d7..4ee4617de9 100644
--- a/lisp/indent.el
+++ b/lisp/indent.el
@@ -597,7 +597,7 @@ indent-relative
 considered.
 
 If the previous nonblank line has no indent points beyond the
-column point starts at, then `tab-to-tab-stop' is done, if both
+column point starts at, then `tab-to-tab-stop' is done if both
 FIRST-ONLY and UNINDENTED-OK are nil, otherwise nothing is done
 in this case.
 
@@ -627,7 +627,7 @@ indent-relative
              (if (> opoint (point))
                  (goto-char opoint))
              (move-marker opoint nil)))
-          (unindented-ok nil)
+          ((or unindented-ok first-only) nil)
           (t (tab-to-tab-stop)))))
 
 (defcustom tab-stop-list nil