122904 - uninitialized nsresult's may be returned by several functions in content/html/document/src

Status: VERIFIED FIXED

(Core :: DOM: HTML Parser, defect)

Description

[Aleksey Nogin]

There are 3 "xxx might be used uninitialized in this function" warnings in
content/html/document/src:

content/html/document/src/nsHTMLDocument.cpp:561
 `nsresult rv' might be used uninitialized in this function

content/html/document/src/nsWyciwygChannel.cpp:353
 `nsresult rv' might be used uninitialized in this function

content/html/document/src/nsWyciwygChannel.cpp:563
 `nsresult rv' might be used uninitialized in this function

The first one have been there for a while, and the last two were introduced by
today's commit by [e-mail] for bug 35340.

All three seem to be real bugs:

- nsHTMLDocument::TryUserForcedCharset will try applying NS_SUCCEEDED to an
uninitialized rv when aMarkupDV is null

- nsWyciwygChannel::WriteToCache will return an uninitialized nsresult if
mCacheOutputStream is null and mCacheTransport is not.

- nsWyciwygChannel::Connect will return an uninitialized nsresult if passed
aFirstTime=PR_FALSE while mCacheEntry is null

P.S. Note that there is something else wrong with
nsWyciwygChannel::WriteToCache, the code there is

if (!mCacheTransport && !mCacheOutputStream) {
    ...

    if (mCacheTransport)
      ...;    
  }

Obviously, the second if statement is dead code.

Comment 1

[Aleksey Nogin]

Bug 59652 is a tracking bug for "xxx might be used uninitialized in this
function" warnings. It also has some additional information on this issue.

Comment 2

[Aleksey Nogin]

nsHTMLDocument.cpp warning was fixed by a recent check-in, now only
nsWyciwygChannel.cpp warnings are left.

Comment 3

[Radha on family leave (not reading bugmail)]

Taking from harish. I have the patch ready  as part of anotehr bug and will
checkin shortly. 

Comment 4

[Radha on family leave (not reading bugmail)]

fix checked in. 

Comment 5

[Moied]

Patch is not attached here, Aleksey: can you please verify this fix, Thanks.

Comment 6

[Aleksey Nogin]

Yes, there are currently no "xxx may be used uninitialized" warnings in
content/html/document, so marking as VERIFIED.

P.S. I thought I'd mention the warnings that are there in the rest of content/
just in case somebody here knows how to fix them as well:

content/base/src/nsSelection.cpp:2250
 `class nsIFrame * thisBlock' might be used uninitialized in this function

content/html/style/src/nsCSSParser.cpp:2861
 `enum nsCSSUnit units' might be used uninitialized in this function

content/html/style/src/nsRuleNode.cpp:1793
 `enum nsSystemFontID sysID' might be used uninitialized in this function

content/html/style/src/nsRuleNode.cpp:4103
 `enum nsStyleContentType type' might be used uninitialized in this function

content/shared/src/nsStyleUtil.cpp:415
 `PRInt32 * column' might be used uninitialized in this function

content/xul/templates/src/nsTemplateMatchSet.cpp:257
 `class nsTemplateMatch ** last' might be used uninitialized in this function