pidgin/pidgin

Fix the infinite resizing freeze
release-2.x.y
2022-04-15, Belgin Știrbu
0079467afee4
Fix the infinite resizing freeze

This appears related to libpango somehow, as in Debian
Bullseye, libpango splits URLs with dashes at the end,
but in Debian Bookworm, the URLs are not split with dashes
at the end, and the bug does not appear to be triggered
in Bookworm.

This patch makes the assumption that the gtkimhtml widgets
stored in a PidginConversation normally resize in an
alternating manner. However, when the bug is triggered,
only the "entry" gtkimhtml member of PidginConversation
resizes, so we allow "entry" to resize only up to 3 times
in a row.

Testing Done:
Compiled and tested on several desktop environments on a few
GNU/Linux distros by pasting the link mentioned
here https://issues.imfreedom.org/issue/PIDGIN-17413 moving
the cursor at the beginning of the buffer, and holding
the spacebar pressed.

Bugs closed: PIDGIN-16753, PIDGIN-16999, PIDGIN-17287, PIDGIN-17413, PIDGIN-17430, PIDGIN-17568, PIDGIN-17602

Reviewed at https://reviews.imfreedom.org/r/1342/
/*
* @file circbuffer.h Buffer Utility Functions
* @ingroup core
*/
/* Purple is the legal property of its developers, whose names are too numerous
* to list here. Please refer to the COPYRIGHT file distributed with this
* source distribution.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111-1301 USA
*/
#include "internal.h"
#include "circbuffer.h"
#define DEFAULT_BUF_SIZE 256
PurpleCircBuffer *
purple_circ_buffer_new(gsize growsize) {
PurpleCircBuffer *buf = g_new0(PurpleCircBuffer, 1);
buf->growsize = growsize ? growsize : DEFAULT_BUF_SIZE;
return buf;
}
void purple_circ_buffer_destroy(PurpleCircBuffer *buf) {
g_return_if_fail(buf != NULL);
g_free(buf->buffer);
g_free(buf);
}
static void grow_circ_buffer(PurpleCircBuffer *buf, gsize len) {
gsize in_offset = 0, out_offset = 0;
gsize start_buflen;
g_return_if_fail(buf != NULL);
start_buflen = buf->buflen;
while ((buf->buflen - buf->bufused) < len)
buf->buflen += buf->growsize;
if (buf->inptr != NULL) {
in_offset = buf->inptr - buf->buffer;
out_offset = buf->outptr - buf->buffer;
}
buf->buffer = g_realloc(buf->buffer, buf->buflen);
/* adjust the fill and remove pointer locations */
if (buf->inptr == NULL) {
buf->inptr = buf->outptr = buf->buffer;
} else {
buf->inptr = buf->buffer + in_offset;
buf->outptr = buf->buffer + out_offset;
}
/* If the fill pointer is wrapped to before the remove
* pointer, we need to shift the data */
if (in_offset < out_offset
|| (in_offset == out_offset && buf->bufused > 0)) {
gsize shift_n = MIN(buf->buflen - start_buflen, in_offset);
memcpy(buf->buffer + start_buflen, buf->buffer, shift_n);
/* If we couldn't fit the wrapped read buffer
* at the end */
if (shift_n < in_offset) {
memmove(buf->buffer,
buf->buffer + shift_n,
in_offset - shift_n);
buf->inptr = buf->buffer +
(in_offset - shift_n);
} else {
buf->inptr = buf->buffer +
start_buflen + in_offset;
}
}
}
void purple_circ_buffer_append(PurpleCircBuffer *buf, gconstpointer src, gsize len) {
gsize len_stored;
g_return_if_fail(buf != NULL);
/* Grow the buffer, if necessary */
if ((buf->buflen - buf->bufused) < len)
grow_circ_buffer(buf, len);
/* If there is not enough room to copy all of src before hitting
* the end of the buffer then we will need to do two copies.
* One copy from inptr to the end of the buffer, and the
* second copy from the start of the buffer to the end of src. */
if (buf->inptr >= buf->outptr)
len_stored = MIN(len, buf->buflen - (buf->inptr - buf->buffer));
else
len_stored = len;
if (len_stored > 0)
memcpy(buf->inptr, src, len_stored);
if (len_stored < len) {
memcpy(buf->buffer, (char*)src + len_stored, len - len_stored);
buf->inptr = buf->buffer + (len - len_stored);
} else {
buf->inptr += len_stored;
}
buf->bufused += len;
}
gsize purple_circ_buffer_get_max_read(const PurpleCircBuffer *buf) {
gsize max_read;
g_return_val_if_fail(buf != NULL, 0);
if (buf->bufused == 0)
max_read = 0;
else if ((buf->outptr - buf->inptr) >= 0)
max_read = buf->buflen - (buf->outptr - buf->buffer);
else
max_read = buf->inptr - buf->outptr;
return max_read;
}
gboolean purple_circ_buffer_mark_read(PurpleCircBuffer *buf, gsize len) {
g_return_val_if_fail(buf != NULL, FALSE);
g_return_val_if_fail(purple_circ_buffer_get_max_read(buf) >= len, FALSE);
buf->outptr += len;
buf->bufused -= len;
/* wrap to the start if we're at the end */
if ((gsize)(buf->outptr - buf->buffer) == buf->buflen)
buf->outptr = buf->buffer;
return TRUE;
}