GNU bug report logs -
#7172
emacs 23.2; xml.el: xml-parse-file hangs when DOCTYPE element names contain _ (underscore)
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owner <at> debbugs.gnu.org, bug-gnu-emacs <at> gnu.org
:
bug#7172
; Package
emacs
.
(Thu, 07 Oct 2010 17:05:02 GMT)
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Acknowledgement sent
to
Jose Marino <marinoj <at> astro.ufl.edu>
:
New bug report received and forwarded. Copy sent to
bug-gnu-emacs <at> gnu.org
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(Thu, 07 Oct 2010 17:05:02 GMT)
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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):
In a DOCTYPE construction, whenever there's an ELEMENT name with an
underscore in its name, function xml-parse-file makes emacs become
unresponsive and use 100% cpu. Emacs recovers nicely with C-g but no
error is printed.
To reproduce this behavior I set up these two simple xml files:
------------ output --------------
$ cat example-good.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE EXAMPLE [
<!ELEMENT EXAMPLE EMPTY>
]>
<EXAMPLE>
</EXAMPLE>
$ cat example-bad.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE EXAMPLE [
<!ELEMENT EXAM_PLE EMPTY>
]>
<EXAM_PLE>
</EXAM_PLE>
------------ output --------------
Then from emacs I run:
(xml-parse-file "example-good.xml")
Which as expected produces:
((EXAMPLE nil "
"))
But when I do the same for the other file:
(xml-parse-file "example-bad.xml")
No output is produced and emacs becomes unresponsive.
Attaching strace to the running emacs process prints:
brk(0x267b000) = 0x267b000
brk(0x269d000) = 0x269d000
brk(0x2637000) = 0x2637000
brk(0x2659000) = 0x2659000
brk(0x267b000) = 0x267b000
brk(0x269d000) = 0x269d000
brk(0x2637000) = 0x2637000
brk(0x2659000) = 0x2659000
brk(0x267b000) = 0x267b000
brk(0x269d000) = 0x269d000
brk(0x2637000) = 0x2637000
brk(0x2659000) = 0x2659000
These messages repeat over and over.
I should mention that this behavior seems to be triggered by the
underscore in the DOCTYPE ELEMENT name, and is not affected by the
underscore in the actual element's name. Thus, this file also triggers
the bug:
$ cat example-bad2.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE EXAMPLE [
<!ELEMENT EXAM_PLE EMPTY>
]>
<EXAMPLE>
</EXAMPLE>
Information forwarded
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owner <at> debbugs.gnu.org, bug-gnu-emacs <at> gnu.org
:
bug#7172
; Package
emacs
.
(Fri, 08 Oct 2010 00:37:02 GMT)
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Message #8 received at 7172 <at> debbugs.gnu.org (full text, mbox):
Jose Marino wrote:
> Attaching strace to the running emacs process prints:
> brk(0x267b000) = 0x267b000
A much more useful thing to do in such cases is to
M-x toggle-debug-on-quit
beforehand, then interrupt Emacs with C-g when it hangs. Resulting backtrace:
Debugger entered--Lisp error: (quit)
looking-at("<!ATTLIST[ \n
]*\\([[:alpha:]:_][-[:digit:].[:alpha:]:_]*\\)[ \n
]*\\(\\(?:[ \n
]*[[:alpha:]:_][-[:digit:].[:alpha:]:_]*[ \n
]*\\(?:CDATA\\|\\(?:ID\\|IDREF\\|IDREFS\\|ENTITY\\|ENTITIES\\|NMTOKEN\\|NMTOKENS\\)\\|\\(?:NOTATION[ \n
]([ \n
]*[[:alpha:]:_][-[:digit:].[:alpha:]:_]*\\(?:[ \n
]*|[ \n
]*[[:alpha:]:_][-[:digit:].[:alpha:]:_]*\\)*[ \n
]*)\\)\\|\\(?:\\(?:NOTATION[ \n
]([ \n
]*[[:alpha:]:_][-[:digit:].[:alpha:]:_]*\\(?:[ \n
]*|[ \n
]*[[:alpha:]:_][-[:digit:].[:alpha:]:_]*\\)*[ \n
]*)\\)\\|\\(?:([ \n
]*[-[:digit:].[:alpha:]:_]+\\(?:[ \n
]*|[ \n
]*[-[:digit:].[:alpha:]:_]+\\)*[ \n
])\\)\\)\\)[ \n
]*\\(?:#REQUIRED\\|#IMPLIED\\|\\(?:#FIXED[ \n
]\\)*\\(?:\"\\(?:[^&\"]\\|\\(?:&[[:alpha:]:_][-[:digit:].[:alpha:]:_]*;\\|\\(?:&#[0-9]+;\\|&#x[0-9a-fA-F]+;\\)\\)\\)*\"\\|'\\(?:[^&']\\|\\(?:&[[:alpha:]:_][-[:digit:].[:alpha:]:_]*;\\|\\(?:&#[0-9]+;\\|&#x[0-9a-fA-F]+;\\)\\)\\)*'\\)\\)\\)\\)*[ \n
]*>")
xml-parse-dtd(nil)
xml-parse-tag(nil nil)
xml-parse-tag(nil nil)
xml-parse-region(1 116 #<buffer *temp*> nil nil)
xml-parse-file("example-bad.xml")
That certainly is a regexp.
Information forwarded
to
bug-gnu-emacs <at> gnu.org
:
bug#7172
; Package
emacs
.
(Sun, 01 Jul 2012 11:05:02 GMT)
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Message #11 received at 7172 <at> debbugs.gnu.org (full text, mbox):
Jose Marino <marinoj <at> astro.ufl.edu> writes:
> In a DOCTYPE construction, whenever there's an ELEMENT name with an
> underscore in its name, function xml-parse-file makes emacs become
> unresponsive and use 100% cpu. Emacs recovers nicely with C-g but no
> error is printed.
>
> $ cat example-bad.xml
> <?xml version="1.0" encoding="utf-8"?>
> <!DOCTYPE EXAMPLE [
> <!ELEMENT EXAM_PLE EMPTY>
> ]>
> <EXAM_PLE>
> </EXAM_PLE>
This is fixed in trunk. Thanks for the bug report.
bug closed, send any further explanations to
7172 <at> debbugs.gnu.org and Jose Marino <marinoj <at> astro.ufl.edu>
Request was from
Chong Yidong <cyd <at> gnu.org>
to
control <at> debbugs.gnu.org
.
(Sun, 01 Jul 2012 11:05:03 GMT)
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Information forwarded
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bug-gnu-emacs <at> gnu.org
:
bug#7172
; Package
emacs
.
(Sun, 01 Jul 2012 11:06:01 GMT)
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bug archived.
Request was from
Debbugs Internal Request <help-debbugs <at> gnu.org>
to
internal_control <at> debbugs.gnu.org
.
(Sun, 29 Jul 2012 11:24:04 GMT)
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This bug report was last modified 11 years and 294 days ago.
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