[4379] in SIPB bug reports
bug in Mosaic 2.2
daemon@ATHENA.MIT.EDU (jsc@slayer.mit.edu)
Sun Feb 13 04:22:11 1994
From: jsc@slayer.mit.edu
Date: Sun, 13 Feb 1994 04:21:51 -0500
To: mosaic-x@ncsa.uiuc.edu
Cc: bug-sipb@MIT.EDU
Reply-To: jsc@MIT.EDU
System: Linux pl15b running X386 v2.0
Symptoms: I type 'Mosaic file://localhost/home/jsc/www/home.html' and
Mosaic dies with a core dump and congratulates me for having found a bug
in it.
stack trace: Using gdb on the core file just told me that it finished in
_end, which itself was under _entry. Hm, not very useful, so I stepped
through it until it died. Here's the stack trace a few lines before
that.
(gdb) where
#0 HideWidgets (hw=0xebc00) at HTMLwidgets.c:1461
#1 0x5943f in HTMLSetText (w=0xebc00,
text=0x105000 "<TITLE>Slayer WWW Home Page</TITLE>\n\nThis home page is here so Mosaic will start up a little quicker.\n", header_text=0xdedc "",
footer_text=0xdedc "", element_id=0, target_anchor=0xb0810 "", ptr=0x0)
at HTML.c:5444
#2 0xdf75 in mo_set_text (w=0xebc00,
txt=0x105000 "<TITLE>Slayer WWW Home Page</TITLE>\n\nThis home page is here so Mosaic will start up a little quicker.\n", ans=0x0, id=0,
target_anchor=0xb0810 "", cached_stuff=0x0) at gui-documents.c:183
#3 0xe150 in mo_do_window_text (win=0xd8800,
url=0xbffffc6b "file://localhost/home/jsc/www/home.html",
txt=0x105000 "<TITLE>Slayer WWW Home Page</TITLE>\n\nThis home page is here so Mosaic will start up a little quicker.\n",
txthead=0x105000 "<TITLE>Slayer WWW Home Page</TITLE>\n\nThis home page is here so Mosaic will start up a little quicker.\n", register_visit=1, ref=0x0)
at gui-documents.c:286
#4 0xe9e9 in mo_load_window_text (win=0xd8800,
url=0xbffffc6b "file://localhost/home/jsc/www/home.html", ref=0x0)
at gui-documents.c:686
#5 0x5922 in mo_open_window (parent=0xbc800,
url=0xbffffc6b "file://localhost/home/jsc/www/home.html", parentw=0x0)
at gui.c:1714
#6 0x5b7f in fire_er_up (w=0x1, client_data=0xbffffa8c, call_data=0x1)
at gui.c:1864
#7 0x602b7676 in _end ()
#8 0x602b7833 in _end ()
#9 0x602b0b33 in _end ()
#10 0x65cb in mo_do_gui (argc=2, argv=0xbffffbc8) at gui.c:2227
#11 0x5a2 in main (argc=2, argv=0xbffffbc8) at main.c:168
It actually dies in XmUpdateDisplay. Some relevant information:
HideWidgets is called with argument hw. I tried running it with the
default home page and again with my own home page, and printing out hw
both times and noting the differences. The only difference was that
hw.drawGC was NULL in the second case.
What I think is happening: drawGC is only set in the DrawExpose
callback. When Mosaic starts up with a home page on the localhost,
it gets it so fast that the html widget doesn't get a chance to get an
expose event before it tries to put up the text. This ends up trying to
update the display without a valid GC.
Please let me know if I can provide any other information that would be
helpful.
-Jin
