unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
* bug#23726: 25.0.94; emacs 25.0.94 crashes
@ 2016-06-08 10:21 Jan Synáček
  2016-06-08 16:49 ` Eli Zaretskii
  2016-06-08 17:32 ` bug#23726: " Paul Eggert
  0 siblings, 2 replies; 7+ messages in thread
From: Jan Synáček @ 2016-06-08 10:21 UTC (permalink / raw)
  To: 23726


Emacs 25.0.94 crashes on the current (Jun 8) Fedora Rawhide. The crash
is reproducible with vanilla upstream sources.

gcc-6.1.1-2.fc25.x86_64
glibc-2.23.90-19.fc25.x86_64

Steps to reproduce:
1) configure --with-x=no
2) make; make install
3) emacs (or emacs -Q)

Note that the crash doesn't always happen. I suspect something fishy
going on with emacs' memory management, as can be seen from the
following.

Valgrind output:

==1274== Memcheck, a memory error detector
==1274== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al.
==1274== Using Valgrind-3.11.0 and LibVEX; rerun with -h for copyright info
==1274== Command: /usr/bin/emacs-nox
==1274== 
==1274== Invalid free() / delete / delete[] / realloc()
==1274==    at 0x4C2FC47: realloc (vg_replace_malloc.c:785)
==1274==    by 0x5628E0: lrealloc (alloc.c:1427)
==1274==    by 0x561FCC: xrealloc (alloc.c:856)
==1274==    by 0x5622CB: xpalloc (alloc.c:978)
==1274==    by 0x40D34E: realloc_glyph_pool (dispnew.c:1344)
==1274==    by 0x40E04D: adjust_frame_glyphs_for_frame_redisplay (dispnew.c:2006)
==1274==    by 0x40D87B: adjust_frame_glyphs (dispnew.c:1791)
==1274==    by 0x418A89: adjust_frame_size (frame.c:587)
==1274==    by 0x4161EE: change_frame_size_1 (dispnew.c:5513)
==1274==    by 0x416244: change_frame_size (dispnew.c:5545)
==1274==    by 0x4172FD: init_display (dispnew.c:6083)
==1274==    by 0x4E76AA: main (emacs.c:1549)
==1274==  Address 0xc1b020 is in a rw- mapped file /usr/bin/emacs-25.0.94-nox segment
==1274== 
emacs: Memory exhausted--use M-x save-some-buffers then exit and restart Emacs
==1274== 
==1274== HEAP SUMMARY:
==1274==     in use at exit: 124,222 bytes in 729 blocks
==1274==   total heap usage: 1,452 allocs, 723 frees, 678,431 bytes allocated
==1274== 
==1274== LEAK SUMMARY:
==1274==    definitely lost: 0 bytes in 0 blocks
==1274==    indirectly lost: 0 bytes in 0 blocks
==1274==      possibly lost: 0 bytes in 0 blocks
==1274==    still reachable: 124,222 bytes in 729 blocks
==1274==         suppressed: 0 bytes in 0 blocks
==1274== Rerun with --leak-check=full to see details of leaked memory
==1274== 
==1274== For counts of detected and suppressed errors, rerun with: -v
==1274== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)


GDB full backtrace:

Starting program: /usr/bin/emacs-nox 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Program received signal SIGABRT, Aborted.
0x00007ffff58378d5 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
54	  return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
Missing separate debuginfos, use: dnf debuginfo-install alsa-lib-1.1.1-1.fc25.x86_64 dbus-libs-1.11.2-1.fc25.x86_64 gmp-6.1.0-3.fc25.x86_64 gnutls-3.4.12-1.fc25.x86_64 gpm-libs-1.20.7-9.fc24.x86_64 libacl-2.2.52-11.fc24.x86_64 libattr-2.4.47-16.fc24.x86_64 libcap-2.25-2.fc25.x86_64 libffi-3.1-9.fc24.x86_64 libgcc-6.1.1-2.fc25.x86_64 libgcrypt-1.6.4-2.fc24.x86_64 libgpg-error-1.21-3.fc25.x86_64 libidn-1.32-2.fc24.x86_64 libjpeg-turbo-1.4.90-1.fc25.x86_64 libselinux-2.5-6.fc25.x86_64 libtasn1-4.8-1.fc25.x86_64 libxml2-2.9.3-3.fc24.x86_64 lz4-r131-2.fc24.x86_64 ncurses-libs-6.0-5.20160116.fc25.x86_64 nettle-3.2-2.fc24.x86_64 p11-kit-0.23.2-2.fc24.x86_64 pcre-8.39-0.1.RC1.fc25.x86_64 systemd-libs-230-2.fc25.x86_64 xz-libs-5.2.2-2.fc24.x86_64 zlib-1.2.8-10.fc24.x86_64
#0  0x00007ffff58378d5 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
        resultvar = 0
        pid = 1204
        selftid = 1204
#1  0x00007ffff58394da in __GI_abort () at abort.c:89
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x0, sa_sigaction = 0x0}, sa_mask = {__val = {0, 10, 4160432, 140737488341312, 6096828, 140737488341744, 3, 3086, 30, 114, 140737488340512, 
              21627284, 16, 21627281, 15, 14}}, sa_flags = -11336, sa_restorer = 0x0}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00000000005605b8 in re_match_2_internal (bufp=0xba9f18 <searchbufs+2552>, string1=0x0, size1=0, string2=0x14a30e0 "/root/scratch/.", size2=15, pos=14, regs=0x0, stop=15)
    at ../../src/regex.c:6223
        mcnt = 3
        reg = 1
        end1 = 0x0
        end2 = 0x14a30ef ""
        end_match_1 = 0x0
        end_match_2 = 0x14a30ef ""
        d = 0x14a30ef ""
        dend = 0x14a30ef ""
        dfail = 0x14a30ee "."
        p = 0x14a0194 "\n;\002\001z\r#"
        pend = 0x14a024b ""
        translate = 2
        multibyte = 0 '\000'
        target_multibyte = 1 '\001'
        fail_stack = {stack = 0x7fffffffc620, size = 20, avail = 6, frame = 6}
        num_regs = 1
        regstart = 0x0
        regend = 0x0
        best_regs_set = 0
        best_regstart = 0x0
        best_regend = 0x0
        match_end = 0x0
        sa_avail = 13184
        sa_count = 5
        sa_must_free = false
#3  0x0000000000559504 in re_search_2 (bufp=0xba9f18 <searchbufs+2552>, str1=0x0, size1=0, str2=0x14a30e0 "/root/scratch/.", size2=15, startpos=14, range=1, regs=0x0, stop=15)
    at ../../src/regex.c:4446
        val = 39840
        string1 = 0x0
        string2 = 0x14a30e0 "/root/scratch/."
        fastmap = 0xba9f58 <searchbufs+2616> ""
        translate = 2
        total_size = 15
        endpos = 15
        anchored_start = 0 '\000'
        multibyte = 1 '\001'
#4  0x0000000000558b0b in re_search (bufp=0xba9f18 <searchbufs+2552>, string=0x14a30e0 "/root/scratch/.", size=15, startpos=0, range=15, regs=0x0) at ../../src/regex.c:4228
No locals.
#5  0x00000000005453d8 in fast_string_match_internal (regexp=9839060, string=20554964, table=0) at ../../src/search.c:476
        val = 140737488345072
        bufp = 0xba9f18 <searchbufs+2552>
#6  0x00000000004e3be7 in fast_string_match (regexp=9839060, string=20554964) at ../../src/lisp.h:4008
No locals.
#7  0x000000000052bc85 in Ffind_file_name_handler (filename=20554964, operation=17376) at ../../src/fileio.c:292
        string = 9839060
        match_pos = 17376
        handler = 4750192
        operations = 16881011
        elt = 16880035
        chain = 16880019
        inhibited_handlers = 0
        result = 0
        pos = -1
#8  0x000000000052c865 in Fexpand_file_name (name=20554964, default_directory=0) at ../../src/fileio.c:809
        nm = 0xba9ae0 <searchbufs+1472> "\260\367I\001"
        nmlim = 0x589b6f <push_handler_nosignal+195> "H\211\302H\213E\370H\211\220\b\001"
        newdir = 0x7fffffffd910 ""
        newdirlim = 0xe <error: Cannot access memory at address 0xe>
        target = 0x100bd4ff0 <error: Cannot access memory at address 0x100bd4ff0>
        tlen = 5806737
        pw = 0x9ba0
        length = 14
        nbytes = 20554992
        handler = 5119553
        result = 0
        handled_name = 11820231
        multibyte = false
        hdir = 21611136
        sa_avail = 16384
        sa_count = 5
        sa_must_free = false
#9  0x00000000005899a8 in internal_condition_case_2 (bfun=0x52c7f3 <Fexpand_file_name>, arg1=20554964, arg2=0, handlers=39840, hfun=0x590563 <Fidentity>) at ../../src/eval.c:1360
        val = 5119553
        c = 0x149c280
#10 0x000000000053a47d in Ffile_attributes (filename=20554964, id_format=0) at ../../src/dired.c:902
        encoded = 5121337
        handler = 8840264
#11 0x000000000058cd30 in Ffuncall (nargs=2, args=0x7fffffffdb10) at ../../src/eval.c:2696
        internal_argbuf = {20554964, 0, 12406768, 1785210630162692608, 0, 0, 10035109, 50}
        fun = 8840269
        original_fun = 18192
        funcar = 0
        numargs = 1
        lisp_numargs = 6
        val = 1
        internal_args = 0x7fffffffda90
        count = 4
#12 0x00000000005d13d7 in exec_byte_code (bytestr=10035076, vector=10035109, maxdepth=50, args_template=2, nargs=0, args=0x7fffffffdfc0) at ../../src/bytecode.c:880
        targets = {0x5d52bb <exec_byte_code+19422>, 0x5d531a <exec_byte_code+19517>, 0x5d531c <exec_byte_code+19519>, 0x5d531e <exec_byte_code+19521>, 0x5d5320 <exec_byte_code+19523>, 
          0x5d5320 <exec_byte_code+19523>, 0x5d5391 <exec_byte_code+19636>, 0x5d540c <exec_byte_code+19759>, 0x5d0b86 <exec_byte_code+1193>, 0x5d0b88 <exec_byte_code+1195>, 
          0x5d0b8a <exec_byte_code+1197>, 0x5d0b8c <exec_byte_code+1199>, 0x5d0b8e <exec_byte_code+1201>, 0x5d0b8e <exec_byte_code+1201>, 0x5d0b97 <exec_byte_code+1210>, 
          0x5d0b4f <exec_byte_code+1138>, 0x5d1097 <exec_byte_code+2490>, 0x5d1099 <exec_byte_code+2492>, 0x5d109b <exec_byte_code+2494>, 0x5d109d <exec_byte_code+2496>, 
          0x5d109f <exec_byte_code+2498>, 0x5d109f <exec_byte_code+2498>, 0x5d10dd <exec_byte_code+2560>, 0x5d10a8 <exec_byte_code+2507>, 0x5d12c2 <exec_byte_code+3045>, 
          0x5d12c4 <exec_byte_code+3047>, 0x5d12c6 <exec_byte_code+3049>, 0x5d12c8 <exec_byte_code+3051>, 0x5d12ca <exec_byte_code+3053>, 0x5d12ca <exec_byte_code+3053>, 
          0x5d1273 <exec_byte_code+2966>, 0x5d128d <exec_byte_code+2992>, 0x5d1395 <exec_byte_code+3256>, 0x5d1397 <exec_byte_code+3258>, 0x5d1399 <exec_byte_code+3260>, 
          0x5d139b <exec_byte_code+3262>, 0x5d139d <exec_byte_code+3264>, 0x5d139d <exec_byte_code+3264>, 0x5d1346 <exec_byte_code+3177>, 0x5d1360 <exec_byte_code+3203>, 
          0x5d146b <exec_byte_code+3470>, 0x5d146d <exec_byte_code+3472>, 0x5d146f <exec_byte_code+3474>, 0x5d1471 <exec_byte_code+3476>, 0x5d1473 <exec_byte_code+3478>, 
          0x5d1473 <exec_byte_code+3478>, 0x5d141c <exec_byte_code+3391>, 0x5d1436 <exec_byte_code+3417>, 0x5d254f <exec_byte_code+7794>, 0x5d23d7 <exec_byte_code+7418>, 
          0x5d23cb <exec_byte_code+7406>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 
          0x5d52bb <exec_byte_code+19422>, 0x5d27dd <exec_byte_code+8448>, 0x5d28e5 <exec_byte_code+8712>, 0x5d2954 <exec_byte_code+8823>, 0x5d29c4 <exec_byte_code+8935>, 
          0x5d2a38 <exec_byte_code+9051>, 0x5d0ecf <exec_byte_code+2034>, 0x5d0f5c <exec_byte_code+2175>, 0x5d2ac1 <exec_byte_code+9188>, 0x5d0e12 <exec_byte_code+1845>, 
          0x5d0fd9 <exec_byte_code+2300>, 0x5d2b38 <exec_byte_code+9307>, 0x5d2bb5 <exec_byte_code+9432>, 0x5d2c0c <exec_byte_code+9519>, 0x5d2c89 <exec_byte_code+9644>, 
          0x5d2cea <exec_byte_code+9741>, 0x5d2de2 <exec_byte_code+9989>, 0x5d2e39 <exec_byte_code+10076>, 0x5d2eb6 <exec_byte_code+10201>, 0x5d2f56 <exec_byte_code+10361>, 
          0x5d2fad <exec_byte_code+10448>, 0x5d3004 <exec_byte_code+10535>, 0x5d3081 <exec_byte_code+10660>, 0x5d30fe <exec_byte_code+10785>, 0x5d317b <exec_byte_code+10910>, 
          0x5d321b <exec_byte_code+11070>, 0x5d327c <exec_byte_code+11167>, 0x5d32dd <exec_byte_code+11264>, 0x5d33d5 <exec_byte_code+11512>, 0x5d347a <exec_byte_code+11677>, 
          0x5d351f <exec_byte_code+11842>, 0x5d37ae <exec_byte_code+12497>, 0x5d3830 <exec_byte_code+12627>, 0x5d38b2 <exec_byte_code+12757>, 0x5d3934 <exec_byte_code+12887>, 
          0x5d39b6 <exec_byte_code+13017>, 0x5d3a17 <exec_byte_code+13114>, 0x5d3ac0 <exec_byte_code+13283>, 0x5d3b21 <exec_byte_code+13380>, 0x5d3b82 <exec_byte_code+13477>, 
          0x5d3be3 <exec_byte_code+13574>, 0x5d3d22 <exec_byte_code+13893>, 0x5d2218 <exec_byte_code+6971>, 0x5d3d90 <exec_byte_code+14003>, 0x5d3de7 <exec_byte_code+14090>, 
          0x5d3ed7 <exec_byte_code+14330>, 0x5d3f45 <exec_byte_code+14440>, 0x5d3fb3 <exec_byte_code+14550>, 0x5d400a <exec_byte_code+14637>, 0x5d4067 <exec_byte_code+14730>, 
          0x5d40c4 <exec_byte_code+14823>, 0x5d4129 <exec_byte_code+14924>, 0x5d52bb <exec_byte_code+19422>, 0x5d4190 <exec_byte_code+15027>, 0x5d41e2 <exec_byte_code+15109>, 
          0x5d4234 <exec_byte_code+15191>, 0x5d4286 <exec_byte_code+15273>, 0x5d42d8 <exec_byte_code+15355>, 0x5d432a <exec_byte_code+15437>, 0x5d2218 <exec_byte_code+6971>, 
          0x5d52bb <exec_byte_code+19422>, 0x5d4381 <exec_byte_code+15524>, 0x5d43e2 <exec_byte_code+15621>, 0x5d4439 <exec_byte_code+15708>, 0x5d4490 <exec_byte_code+15795>, 
          0x5d450d <exec_byte_code+15920>, 0x5d458a <exec_byte_code+16045>, 0x5d45e1 <exec_byte_code+16132>, 0x5d46ec <exec_byte_code+16399>, 0x5d4769 <exec_byte_code+16524>, 
          0x5d47e6 <exec_byte_code+16649>, 0x5d4863 <exec_byte_code+16774>, 0x5d48b5 <exec_byte_code+16856>, 0x5d52bb <exec_byte_code+19422>, 0x5d2131 <exec_byte_code+6740>, 
          0x5d1537 <exec_byte_code+3674>, 0x5d0caa <exec_byte_code+1485>, 0x5d166c <exec_byte_code+3983>, 0x5d17d4 <exec_byte_code+4343>, 0x5d1930 <exec_byte_code+4691>, 
          0x5d20ae <exec_byte_code+6609>, 0x5d20f1 <exec_byte_code+6676>, 0x5d1211 <exec_byte_code+2868>, 0x5d21c9 <exec_byte_code+6892>, 0x5d2255 <exec_byte_code+7032>, 
          0x5d22f8 <exec_byte_code+7195>, 0x5d2347 <exec_byte_code+7274>, 0x5d2599 <exec_byte_code+7868>, 0x5d2630 <exec_byte_code+8019>, 0x5d26d0 <exec_byte_code+8179>, 
          0x5d2745 <exec_byte_code+8296>, 0x5d14e0 <exec_byte_code+3587>, 0x5d490c <exec_byte_code+16943>, 0x5d49ac <exec_byte_code+17103>, 0x5d4a03 <exec_byte_code+17190>, 
          0x5d4a5a <exec_byte_code+17277>, 0x5d4ab1 <exec_byte_code+17364>, 0x5d4b08 <exec_byte_code+17451>, 0x5d4b85 <exec_byte_code+17576>, 0x5d4c02 <exec_byte_code+17701>, 
          0x5d4c7f <exec_byte_code+17826>, 0x5d4cfc <exec_byte_code+17951>, 0x5d4e61 <exec_byte_code+18308>, 0x5d4ede <exec_byte_code+18433>, 0x5d4f5b <exec_byte_code+18558>, 
          0x5d4fb2 <exec_byte_code+18645>, 0x5d502f <exec_byte_code+18770>, 0x5d50ac <exec_byte_code+18895>, 0x5d5111 <exec_byte_code+18996>, 0x5d5176 <exec_byte_code+19097>, 
          0x5d3c44 <exec_byte_code+13671>, 0x5d3ca5 <exec_byte_code+13768>, 0x5d51d7 <exec_byte_code+19194>, 0x5d524b <exec_byte_code+19310>, 0x5d52bb <exec_byte_code+19422>, 
          0x5d1a8c <exec_byte_code+5039>, 0x5d1b94 <exec_byte_code+5303>, 0x5d1cdb <exec_byte_code+5630>, 0x5d1e22 <exec_byte_code+5957>, 0x5d1f68 <exec_byte_code+6283>, 
          0x5d2d4b <exec_byte_code+9838>, 0x5d333e <exec_byte_code+11361>, 0x5d3e40 <exec_byte_code+14179>, 0x5d54ae <exec_byte_code+19921>, 0x5d552c <exec_byte_code+20047>, 
          0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d55d1 <exec_byte_code+20212>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 
          0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 
          0x5d52bb <exec_byte_code+19422>, 0x5d52bb <exec_byte_code+19422>, 0x5d5676 <exec_byte_code+20377> <repeats 64 times>}
        count = 4
        op = 1
        vectorp = 0x991fa8 <pure+1192200>
        stack = {
          pc = 0xad7d00 <pure+2526816> "\356\357\f!\360P!\232\204-\001\361\362\002P\016D\"\026D\210\016E<\203T\001\r\324=\203>\001Ղ@\001\016C\331\332\333\334\335\336\006\006!\363\"\340\341%\016E\"\026E\210\f\203_\001\364\f!\024\202d\001\365\366\367\"\210\016F\332\370\371\335\336\005!\372\"\373$\216\374 \210)\210\375\376\377\"\210\201H", byte_string = 10035076, 
          byte_string_start = 0xad7be7 <pure+2526535> "\b\203\b", next = 0x0}
        top = 0x7fffffffdb10
        result = 64288067697
        type = CATCHER
#13 0x000000000058d620 in funcall_lambda (fun=10035029, nargs=0, arg_vector=0x7fffffffdfc0) at ../../src/eval.c:2855
        size = 5
        val = 0
        syms_left = 2
        next = 2
        lexenv = 12406768
        count = 4
        i = 140737354130560
        optional = false
        rest = false
#14 0x000000000058d398 in apply_lambda (fun=10035029, args=0, count=3) at ../../src/eval.c:2794
        args_left = 0
        i = 0
        numargs = 0
        arg_vector = 0x7fffffffdfc0
        tem = 10035029
        sa_avail = 16384
        sa_count = 4
        sa_must_free = false
#15 0x000000000058b8dd in eval_sub (form=17290403) at ../../src/eval.c:2211
        fun = 10035029
        val = 17141888
        original_fun = 8666816
        original_args = 0
        funcar = 25104
        count = 3
        argvals = {12645440, 12245584, 5119553, 17141888, 140737488347504, 5824004, 0, 25104}
#16 0x000000000058adca in Feval (form=17290403, lexical=0) at ../../src/eval.c:1988
        count = 2
#17 0x00000000004ea3c3 in top_level_2 () at ../../src/keyboard.c:1108
No locals.
#18 0x0000000000589869 in internal_condition_case (bfun=0x4ea3a0 <top_level_2>, handlers=16560, hfun=0x4e9e3e <cmd_error>) at ../../src/eval.c:1309
        val = 5119553
        c = 0x149c150
#19 0x00000000004ea408 in top_level_1 (ignore=0) at ../../src/keyboard.c:1116
No locals.
#20 0x0000000000589162 in internal_catch (tag=41088, func=0x4ea3c5 <top_level_1>, arg=0) at ../../src/eval.c:1074
        val = 5119553
        c = 0x1489540
#21 0x00000000004ea2f2 in command_loop () at ../../src/keyboard.c:1077
No locals.
#22 0x00000000004e9a00 in recursive_edit_1 () at ../../src/keyboard.c:684
        count = 1
        val = 5824079
#23 0x00000000004e9b96 in Frecursive_edit () at ../../src/keyboard.c:755
        count = 0
        buffer = 0
#24 0x00000000004e778b in main (argc=1, argv=0x7fffffffe4e8) at ../../src/emacs.c:1606
        dummy = 0
        stack_bottom_variable = 0 '\000'
        do_initial_setlocale = true
        dumping = false
        skip_args = 0
        rlim = {rlim_cur = 8720000, rlim_max = 18446744073709551615}
        no_loadup = false
        junk = 0x0
        dname_arg = 0x0
        ch_to_dir = 0x0
        original_pwd = 0x0


-- 
Jan Synacek
Software Engineer, Red Hat





^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2016-06-09  6:17 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-06-08 10:21 bug#23726: 25.0.94; emacs 25.0.94 crashes Jan Synáček
2016-06-08 16:49 ` Eli Zaretskii
2016-06-08 17:32 ` bug#23726: " Paul Eggert
2016-06-08 18:34   ` Florian Weimer
2016-06-08 18:52     ` Florian Weimer
2016-06-08 18:57       ` Paul Eggert
2016-06-09  6:17       ` Jan Synacek

Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).