You should use attachments, rather than comments, for large chunks of ASCII data, such as trace, debugging output files, or log files. That way, it doesn't bloat the bug for everyone who wants to read it, and cause people to receive fat, useless mails.
You should make sure to trim screenshots. There's no need to show the whole screen if you are pointing out a single-pixel problem.
Bugzilla stores and uses a Content-Type for each attachment (e.g. text/html). To download an attachment as a different Content-Type (e.g. application/xhtml+xml), you can override this using a 'content_type' parameter on the URL, e.g. &content_type=text/plain.
If you have a really large attachment, something that does not need to be recorded forever (as most attachments are), you can mark your attachment as a "Big File", assuming the administrator of the installation has enabled this feature. Big Files are stored directly on disk instead of in the database, and can be deleted when it is no longer needed. The maximum size of a "Big File" is normally larger than the maximum size of a regular attachment.
Viewing and reviewing patches in Bugzilla is often difficult due to lack of context, improper format and the inherent readability issues that raw patches present. Patch Viewer is an enhancement to Bugzilla designed to fix that by offering increased context, linking to sections, and integrating with Bonsai, LXR and CVS.
Patch viewer allows you to:
|View patches in color, with side-by-side view rather than trying to interpret the contents of the patch.|
|See the difference between two patches.|
|Get more context in a patch.|
|Collapse and expand sections of a patch for easy reading.|
|Link to a particular section of a patch for discussion or review|
|Go to Bonsai or LXR to see more context, blame, and cross-references for the part of the patch you are looking at|
|Create a rawtext unified format diff out of any patch, no matter what format it came from|
The main way to view a patch in patch viewer is to click on the "Diff" link next to a patch in the Attachments list on a bug. You may also do this within the edit window by clicking the "View Attachment As Diff" button in the Edit Attachment screen.
To see the difference between two patches, you must first view the newer patch in Patch Viewer. Then select the older patch from the dropdown at the top of the page ("Differences between [dropdown] and this patch") and click the "Diff" button. This will show you what is new or changed in the newer patch.
To get more context in a patch, you put a number in the textbox at the top of Patch Viewer ("Patch / File / [textbox]") and hit enter. This will give you that many lines of context before and after each change. Alternatively, you can click on the "File" link there and it will show each change in the full context of the file. This feature only works against files that were diffed using "cvs diff".
To view only a certain set of files in a patch (for example, if a patch is absolutely huge and you want to only review part of it at a time), you can click the "(+)" and "(-)" links next to each file (to expand it or collapse it). If you want to collapse all files or expand all files, you can click the "Collapse All" and "Expand All" links at the top of the page.
To link to a section of a patch (for example, if you want to be able to give someone a URL to show them which part you are talking about) you simply click the "Link Here" link on the section header. The resulting URL can be copied and used in discussion.
To go to Bonsai to get blame for the lines you are interested in, you can click the "Lines XX-YY" link on the section header you are interested in. This works even if the patch is against an old version of the file, since Bonsai stores all versions of the file.
To go to LXR, you click on the filename on the file header (unfortunately, since LXR only does the most recent version, line numbers are likely to rot).
If the patch is not in a format that you like, you can turn it into a unified diff format by clicking the "Raw Unified" link at the top of the page.