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Re: Corrupted directory output
Re: Corrupted directory output
Sat, 20 Nov 2021 22:00:21 +0000
On Sun, Nov 21, 2021 at 01:40:13AM +1100, Brendan O'Dea wrote:
> Malformed info files cause install-info to produce corrupted dir files.
> See attached example, where the folding info page contains:
> * folding: folding editor minor mode for Emacs
> which results in the corrupted `dir` file in the attached archive.
> I'm submitting a patch to the folding author to fix the @direntry for that
> package, but install-info should probably be more resilient to badly formed
> Some poking around suggests that the problem is in reformat_new_entries,
> where this sequence near the top of the for loop:
> split_entry (entry->text, &name, &name_len, &desc, &desc_len);
> free (entry->text);
> frees entry->text. When format_entry is called at the bottom that loop, it
> exits early due to this condition (desc is NULL):
> if (!desc || !name)
> return 1;
> ...which does not set outstr_out (entry->text), leading to the corruption.
Thanks for tracking it down to this. I'm not very familiar with the code
for install-info at all so it is slow for me to fix. (I'm not familiar
with all the options for install-info either.)
The best I've been able to come up with at the moment is the following:
diff --git a/install-info/install-info.c b/install-info/install-info.c
index e10f492261..32868acbf5 100644
@@ -1542,6 +1542,7 @@ format_entry (char *name, size_t name_len, char *desc,
strncat (outstr, line_out, offset_out);
+ free (*outstr_out);
*outstr_out = outstr;
*outstr_len = strlen (outstr);
@@ -1657,7 +1658,6 @@ reformat_new_entries (struct spec_entry *entries, int
calign_cli, int align_cli,
char *name = NULL, *desc = NULL;
size_t name_len = 0, desc_len = 0;
split_entry (entry->text, &name, &name_len, &desc, &desc_len);
- free (entry->text);
/* Specify sane defaults if we need to */
if (calign_cli == -1 || align_cli == -1)
This works okay (tested). Do you think it is all right? I'll commit this
code soon if nobody has any other ideas.
I couldn't see an easy way in reformat_new_entries to remove the
faulty entry. I'd prefer to fix this in the simplest, least intrusive
way possible so as not to risk breaking something.
I had tried adding error code to set the line to an empty string if
format_entry was going to exit early, but this led to problems later
on in the code (in menu_line_equal) which didn't work for empty strings.
This meant that existing (correct) lines in the dir file would be deleted
due to menu_line_equal incorrectly returning true. Rather than try to fix
this, just pass through the original line unaltered. With your test this
leads to the final output:
File: dir, Node: Top This is the top of the INFO tree
This (the Directory node) gives a menu of major topics.
Typing "q" exits, "H" lists all Info commands, "d" returns here,
"h" gives a primer for first-timers,
"mEmacs<Return>" visits the Emacs manual, etc.
In Emacs, you can click mouse button 2 on a menu item or cross reference
to select it.
* Emacs FAQ: (efaq). Frequently Asked Questions about Emacs.
* folding: folding editor minor mode for Emacs
and I have checked this is idempotent for the input files you sent (running
install-info more than once on the same file doesn't make any more changes).