bug#10034: 24.0.91; max-specpdl-size error

[nyc4bos]

I was playing around with built-in GnuTLS and the funtions
`open-gnutls-stream' and `gnutls-negotiate' to try to get
trustfiles to work on Windows. (GnuTLS doesn't support a "-CApath"
option where you can specify a directory where PEM files lives,
unfortunately, unlike OpenSSL).

I would create a GnuTLS process via:

(with-temp-buffer
(open-gnutls-stream "tls" "tls-buffer" "imap.aim.com" 993))

and

(gnutls-negotiate :process (open-network-stream "tls" "tls-buffer"
                     "imap.aim.com" 993)
                    :type 'gnutls-x509pki
                    :trustfiles trustfiles
                    :hostname host)


When I didn't see a successful verification message, i.e. warnings:

gnutls.c: [1] (Emacs) certificate signer was not found: imap.aim.com

I would kill the "tls-buffer" (hence killing the GnuTLS process) and
the buffer would be killed and I would see the expected message:

gnutls.c: [2] (Emacs) Deallocating x509 credentials

I would then make modifications to the definition of `trustfiles' or
PEM files, etc. and try again.

I would do this iteration many times.

Eventually, I would get into a state where I couldn't do much, seeing
messages like:

window-min-size-1: Variable binding depth exceeds max-specpdl-size

I then could only kill Emacs.


In GNU Emacs 24.0.91.1 (i386-mingw-nt5.1.2600)
 of 2011-11-07 on MARVIN
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.6) --no-opt --cflags 
-I"D:/devel/emacs/libs/libXpm-3.5.8/include" 
-I"D:/devel/emacs/libs/libXpm-3.5.8/src" 
-I"D:/devel/emacs/libs/libpng-dev_1.4.3-1/include" 
-I"D:/devel/emacs/libs/zlib-dev_1.2.5-2/include" 
-I"D:/devel/emacs/libs/giflib-4.1.4-1/include" 
-I"D:/devel/emacs/libs/jpeg-6b-4/include" 
-I"D:/devel/emacs/libs/tiff-3.8.2-1/include" 
-I"D:/devel/emacs/libs/gnutls-2.10.1/include" --ldflags 
-L"D:/devel/emacs/libs/gnutls-2.10.1/lib"'

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US
  value of $XMODIFIERS: nil
  locale-coding-system: cp949
  default enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
  show-paren-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
<return> n <return> C-x b * M e <tab> <return> C-r 
g n u t C-a C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r 
C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r 
C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r C-r 
C-r C-r C-r C-v C-s C-s <help-echo> <help-echo> <help-echo> 
<help-echo> C-x b * s c <tab> C-g <help-echo> <help-echo> 
<help-echo> <help-echo> <help-echo> <help-echo> <menu-bar> 
<help-menu> <send-emacs-bug-report>

Recent messages:
gnutls.c: [2] ASSERT: ../../../src/gnutls-2.10.5/lib/gnutls_record.c:918

gnutls.c: [2] (Emacs) Deallocating x509 credentials
gnutls.c: [2] ASSERT: ../../../src/gnutls-2.10.5/lib/gnutls_buffers.c:601

gnutls.c: [2] ASSERT: ../../../src/gnutls-2.10.5/lib/gnutls_record.c:918

gnutls.c: [2] (Emacs) Deallocating x509 credentials
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