Error: nonexistent files never reported as error

RESOLVED FIXED in mozilla0.9.6



20 years ago
17 years ago


(Reporter: raj, Assigned: rpotts)



Dependency tree / graph

Firefox Tracking Flags

(Not tracked)


(Whiteboard: [PDT-][rtm-], URL)


(2 attachments)



20 years ago
This is in the precompiled M11 Linux binary.

In Communicator 4.x, an error dialog appears, which is much nicer. Also,
a URL like file://asdfsa/ shows the / directory of localhost. Instead,
like 4.x, it should complain that it can't find the server asdfsa.

It doesn't make a difference whether I type the URL directly into the
location text box, or use the Open File menu (and type in a non-existent
file into the file dialog).

The text output looks like this (from first trying file:///asdf, then

Document file:///asdf loaded successfully
Document: Done (0.697 secs)
FindShortcut: in='file://asdf'  out='null'
failed to set the page title.
Document file://asdf/ loaded successfully
Document: Done (1.116 secs)
The other problem with this is that the "blank screen" shown for a missing file
is not added to the history, so when you go back, you go back to whatever you
were on *before* the the page that had the link to the missing file.


20 years ago
Assignee: gagan → travis
Target Milestone: M13

Comment 4

20 years ago
This looks like a webshell issue...  Someone needs to look at the result from
OnEndDocumentLoad(...) and display an error page...

Comment 5

20 years ago
Resetting QA Contact.

Comment 6

20 years ago
Confirmed blank page and no error notification with 1999-12-08-08-M12
nightly binary on Windows NT 4.0sp3  Here is the relevant console output:
  >FindShortcut: in='file:///.html'  out='null'
  >Error: Can't load: file:///.html (8052e891)
  >Error loading URL file:///.html
  >Document: Done (0.661 secs)

The problem mentioned by dbaron in his 11/22/99 comment about [Back] not
working properly after the file:/// load failure looks very much like
bug 13329 "Generic problem with history - skips pages when going back" -
probably fixed now. At least, the history is working for me in this case,
and it does look like there is already a bug for this.

Comment 7

20 years ago
Bulk move of all Networking-Core (to be deleted component) bugs to new
Networking component.


19 years ago
Target Milestone: M13 → M14

Comment 8

19 years ago
Move to M14.  Do we nedd to fix this for beta 1?

Comment 9

19 years ago
*** Bug 22792 has been marked as a duplicate of this bug. ***

Comment 10

19 years ago
*** Bug 26010 has been marked as a duplicate of this bug. ***

Comment 11

19 years ago
*** Bug 26097 has been marked as a duplicate of this bug. ***
Nominating for beta1, because I think this is a basic UI issue.  Also marking
Keywords: 4xp, beta1


19 years ago
Whiteboard: [PDT-]

Comment 13

19 years ago
The MICROSOFT WINDOWS 98 builds also share this flaw.
OS: Linux → All

Comment 14

19 years ago
Move to M16 ...
Target Milestone: M14 → M16

Comment 15

19 years ago
*** Bug 40539 has been marked as a duplicate of this bug. ***

Comment 16

19 years ago
*** Bug 42652 has been marked as a duplicate of this bug. ***

Comment 17

19 years ago
*** Bug 33132 has been marked as a duplicate of this bug. ***

Comment 18

19 years ago
M16 has been out for a while now, these bugs target milestones need to be 

Comment 20

19 years ago
Problem relayed by David Baron (1999-11-22) - blank screen
No longer happens  (previous page continues to be displayed)

There is still no error message when a file is not found (as in Comm 4.x).

Comment 21

19 years ago
Adding mostfreq keyword, and adding "finger" to summary (see dup bug 33132).
Keywords: mostfreq
Summary: Missing file: URL gives a blank page display → Missing file: or finger: URL gives a blank page display
Nominating for rtm as a mostfreq (hoping... ;-) We really should have this. How 
come this bug fell through the net?

Keywords: rtm
adding myself to the cc list.

valeski, you want me to investigate this?
mscott, do you own a duplicate of this?

Comment 25

19 years ago
Are we really getting huge numbers of complaints from beta users about this?
Since the fix for this requires a new dialog and it's too late for UI changes,
I'm marking this rtm-.  (Since there isn't already a patch, it's not likely to
make the train in any case.)
Whiteboard: [PDT-] → [PDT-][rtm-]
Setting milestone to something more sane than "M16". Valeski, if you have better 
thoughts on this, please change it again :-)

Target Milestone: M16 → mozilla0.9

Comment 27

19 years ago
I didn't notice this one before - ftp doesn't report errors either. Neither does
gopher (not in the tree yet) or about: (Although about prints a couple of
NS_ENSURE_TRUE assertions). Retitling, and nominating for moz 0.9

about: may be separate - the others all bring up the directory tree componant.
Keywords: mozilla0.9
Summary: Missing file: or finger: URL gives a blank page display → Only http scheme reports errors

Comment 28

19 years ago
*** Bug 60421 has been marked as a duplicate of this bug. ***

Comment 29

19 years ago
*** Bug 60421 has been marked as a duplicate of this bug. ***

Comment 30

19 years ago
-> gagan
Assignee: valeski → gagan

Comment 31

19 years ago
http bugs to "Networking::HTTP"
Assignee: gagan → darin
Component: Networking → Networking: HTTP
Target Milestone: mozilla0.9 → M19

Comment 32

18 years ago
This isn't Networking:HTTP this is Networking:anything-but-HTTP :)
Component: Networking: HTTP → Networking
Keywords: beta1 → nsbeta1

Comment 33

18 years ago
this really applies to all protocols, it just happens that with HTTP, the server
reports many of the errors by simply sending some HTML content to the client.
this makes it appear as though HTTP is handling errors, when really it is doing
nothing more than displaying content from the server.

in general, error reporting from necko, needs much attention. 

Comment 34

18 years ago
> this really applies to all protocols, it just happens that with HTTP, the
> server reports many of the errors by simply sending some HTML content to the
> client.

Use mozilla to go to There's a pop-up telling you that the
domain doesn't exist. This popup doesn't appear with ftp, or gopher or datetime,
or finger. ftp and gopher use the directory viewer, so that could be hijacking
it, but datetime and finger don't, so there goes that explanation :) I'm not
using a proxy.

This may be a separate bug though.

Comment 35

18 years ago
Just for the record, using TestProtocols for http (or gopher) on an invalid
domain prints out the fact that there was a DNS error, while this doesn't occur
for ftp:

./TestProtocols http://invalid ftp://invalid gopher://invalid
Warning: MOZILLA_FIVE_HOME not set.
Warning: MOZILLA_FIVE_HOME not set.
Type Manifest File: /home/bbaetz/src/mozilla/dist/bin/components/xpti.dat

Trying to load:
WARNING: No disk cache present, file nsCacheManager.cpp, line 179

Finished loading: http://invalid  Status Code: 804b001e
	HTTP Status: 1073797506
	DNS lookup failed.
	Read: 0 bytes.
	Time to connect: 981657289.636 seconds
	Time to read: -981657289.493 seconds.
	Throughput: REAL FAST!!

Finished loading: ftp://invalid  Status Code: 0
	Read: 0 bytes.
	Time to connect: 981657289.672 seconds
	Time to read: -981657289.445 seconds.
	Throughput: REAL FAST!!

Finished loading: gopher://invalid  Status Code: 804b001e
	DNS lookup failed.
	Read: 0 bytes.
	Time to connect: 981657289.680 seconds
	Time to read: -981657289.340 seconds.
	Throughput: REAL FAST!!
CanUnload_enumerate: skipping native

ftp has a return status code of 0, which seems wrong

Comment 36

18 years ago
removed stale rtm keyword.
set target milestone = mozilla0.9
Keywords: rtm
Target Milestone: --- → mozilla0.9

Comment 37

18 years ago
dougt: do you have another bug tracking this for FTP?
Darin, there isn't one bug on this specifically.  However, I believe that I have
already fixed this in the currect changes that I am working on.  

If you like, you can assign this bug to me and I will see that ftp and file both
get fixed.  Or maybe it is better to spawn a bunch of bugs with block this bug?

Comment 39

18 years ago
Doug, yes.. let's make this a meta bug.  I'll leave it to you to add the 
appropriate blocker bugs for ftp:// and file://.

Comment 40

18 years ago
Since this applies to all of necko, I'm pushing the target milestone back to
mozilla1.0.  Dougt has other bugs tracking this problem for file:// and ftp://
with more aggressive targets.
Target Milestone: mozilla0.9 → mozilla1.0
*** Bug 77065 has been marked as a duplicate of this bug. ***
*** Bug 76434 has been marked as a duplicate of this bug. ***

Comment 43

18 years ago
mass move, v2.
qa to me.
QA Contact: tever → benc


18 years ago
Blocks: 77635

Comment 44

18 years ago
changed summary for searchability. This seems to affect lots of areas.

jar affected in bug 26496.
sidebar affected in bug 77635.
No longer blocks: 77635
Depends on: 26496
Keywords: meta
Summary: Only http scheme reports errors → Error: nonexistent files never reported as error


18 years ago
Blocks: 31094

Comment 45

18 years ago
This has regressed yet further: there's no feedback now for http URLs either.
E.g. go to -- it spins on "resolving host"
then changes to "Document: Done" showing a blank page and no error message.
(With a 6/25 build.)  Or is this http problem covered by a different bug?

Comment 46

18 years ago
Whoops, turns out that was specific to the 6/25 build; in 6/27 the dialog is
back for http urls.

Comment 47

18 years ago
yes, this is a different bug which has been fixed. please try a more recent build.
*** Bug 89423 has been marked as a duplicate of this bug. ***


18 years ago
Blocks: 90976


18 years ago
Blocks: 89118


18 years ago
Blocks: 63048


18 years ago
Blocks: 63878


18 years ago
Target Milestone: mozilla1.0 → mozilla0.9.4


18 years ago
Blocks: 95997


18 years ago
Blocks: 33132

Comment 49

18 years ago
-> docshell, necko is producing NS_ERROR_FILE_NOT_FOUND in the file channel's
Component: Networking → Embedding: Docshell

Comment 50

18 years ago
-> reassign
Assignee: darin → adamlock
QA Contact: benc → adamlock

Comment 51

18 years ago
-> 0.9.5 sorry, we can't be dealing w/ existing regressions at the moment.

looks like we just need to respond to file-not-found.
Target Milestone: mozilla0.9.4 → mozilla0.9.5

Comment 52

18 years ago
*** Bug 100307 has been marked as a duplicate of this bug. ***

Comment 53

18 years ago
Entering a duff URL such as file:///c|fdsf/sdfsdfsd appears to partially work.
It generates the correct error message in an alert box but the content area is
displays "<html><body></body></html>" as text.

Comment 54

18 years ago
I see that (empty html source in the content area) fairly frequently for http
urls that do exist.  It's sporadic, and hitting reload usually gives me the real
page.  I don't often see it for nonexistant file urls.  I think it's an
unrelated problem, don't know whether there's a bug filed or not.
I have a patch. It seems like the right thing to do, but I'd like confirmation.
No longer blocks: 89118

Comment 57

18 years ago
oh boy :-)  This opens up a very old can of worms :-)

I believe the current behavior of the FileChannel is due to an (outdated?)
assumption that OnStopRequest *must* be paired with OnStartRequest.

I'm pretty sure that this assumption is violated elsewhere... and i'm not even
sure if necko still publically has this requirement...

If pairing OnStart/OnStop is no longer necessary, then the attached patch looks
correct... Otherwise, I think that we'll need to fix the problem upstream, by
Calling GetStatus(...) and checking for failure... in some stream listener

i'm cc'ing darin to get the 'official' word on whether OnStart/OnStopRequest
*must* be paired or not...


I think that they must be paired, and in fact they are.

What was happening was that the onstart was succeding, so we tore away the
document. Then we got the onstop, and popped up the dialog box, and got
about:blank for our troubles.

Now the onstart fails, so something (uriloader? docshell?) doesn't remove the
document, and the onstop checks the error.

Thats a guess - I haven't traced the code. Does that sound right, though?

Comment 59

18 years ago
OnStartRequest must be paired with an OnStopRequest ... no exceptions!

r=darin on the patch... i forgot to add that line when i added the code to
inherit mStatus from the underlying file transport.  thanks for fixing this :-)

darin: actually, now that I look at the code again, no other protocol does that
:) Whats special about file channels?
Assignee: adamlock → bbaetz

Comment 61

18 years ago
the error is known by the time OnStartRequest is fired, so we should make sure
the channel's status is correctly up-to-date.  this same idea applies to all
channels... even if it is not yet implemented (similarly) elsewhere.

Comment 62

18 years ago
Comment on attachment 50320 [details] [diff] [review]

actually, on second thought, i don't understand how this patch helps with anything.  
returning failure from OnStartRequest causes the request to be canceled.
however, the request should already be "canceled" since there was a file transport error.

we need to better understand why this fix helps, because it can't be the correct fix.
darin and I looked at this, and I've come up with a uriloader patch.

mscott: you checked the original version of this code in way back when - why did
you only check for one specific error code (see the patch)

Comment 65

18 years ago
i'm not convinced that this is correct... mscott: please advise.
No, this breaks ftp, possibly as a side effect of bug 101128, or we could just
not be updating the status.

I think its the right thing to do though.

Comment 67

18 years ago
ProcessCanceledCase cuts off the m_targetStreamListener, making the
OnStopRequest basically a nop.  this means that the code which handles
UNKNOWN_HOST in nsWebShell wouldn't get called, right??
But it works! Try it an see.

Without my patch, though, I don't see how we avoid destroying the current page
for an dns failure with http. mscott? rpotts?

Also note that http is the only protocol to get the error stuff right, and it
only has connection level errors. This does not fill me with confidence that
copy-and-paste of existing code is the right thing to do.

Is there a primer on how webshell/docshell/uriloader/necko are meant to interact?
OK, now that the duplicate-on-stop patch has gone in for ftp, this is good.
_and_ the dns errors for ftp, which load about:blank currently, as for file are
fixed by this.

I am now convinced that this is the correct thing to do. However, I'd really
like some feedback as to why this was done in the first place. Please?
Keywords: patch, review
Target Milestone: mozilla0.9.5 → mozilla0.9.6


18 years ago
Blocks: 104166
Blocks: 100816

Comment 70

18 years ago
rick: bbaetz's patch should look very familar to you :)

Comment 71

18 years ago
-> rpotts
Assignee: bbaetz → rpotts

Comment 72

18 years ago
This is basically the same patch as bug #106558 :-)

i'll leave it open until i land that patch, though -- so i don't lose all of the
blocking bugs...

-- rick
Depends on: 106558
I've been trying to get review on this for almost 5 weeks now from mscott. (I
mailed you on Friday, but you probably haven't got it yet, given what I've been
hearing about the network update)

I still haven't got an answer to the "why was it done this way in the first
place" question....

Comment 74

18 years ago
welcome to the club :-)

the code was originally added to fix bug #40116...  however, over time it has 
been scaled back.  first, the call to ProcessCanceledCase() was removed from 

i believe that the call to ProcessCanceledCase() in OnDataAvailable(...) is 
unnecessary because it should always be safe to call the consumer with data - 
even if an error has occurred...

that just leaves the call within OnStartRequest(...) :-)  

i bet that the original patch was scoped very narrowly to just fix the immediate 
problem (back then NS_BINDING_ABORTED was about the only error code that could 
be passed to OnStartRequest)...

so i believe that short-circuiting on any FAILURE in OnStartRequest(...) is safe 

-- rick

Comment 75

18 years ago
I've checked the patch in for bug #106558.  So this bug should be fixed too.
Last Resolved: 18 years ago
Resolution: --- → FIXED

Comment 76

18 years ago
Is this going to fix all the bugs that are marked blocked, or do those modules
still have to implement error messages?

Comment 77

17 years ago
*** Bug 95997 has been marked as a duplicate of this bug. ***

Comment 78

17 years ago
adam: I can qa this if you want.
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