id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
30509	Various FileResponse fixes and changes	Piotr Kunicki	nobody	"As I've mentioned in PR 11011 (of ticket #30196) I noticed a couple of issues with the way FileResponse is created (and other minor things), and in this ticket I'll try to list and fix them.

For initial clarity, this PR consists of 2 commits. The first is a set of tests, most of which show invalid behavior in some quite specific cases based on current code. The second contains my initial proposed fixes.

1. tests:
 a. {{{test_file_from_buffer_absolute_name}}}:\\
 test ends in an error, because {{{set_headers()}}} attempts to read the 'name' property if the filename (which can be overwritten by the custom filename) is recognized as an absolute path by os.path.
 b. {{{test_file_from_buffer_explicit_type1}}}, {{{test_file_from_buffer_explicit_type2}}}:\\
 of these 2, first test shows the way to explicitly set {{{Content-Type}}} header of the response, while the second shows that in a case that the set value matches the beginning of the default value ({{{'text/html; charset=%s' % self.charset}}}), it will consider that value as unset and proceed to read the content type from the file.
 c. {{{test_file_from_named_buffer1}}}, {{{test_file_from_named_buffer2}}}:\\
 tests show how you can easily 'fool' FileResponse into thinking it's dealing with an actual file, resulting in incorrect header values if such file exists (1) or an error if it doesn't (2).
 d. {{{test_file_from_disk_custom_name}}}, {{{test_file_from_disk_as_attachment_custom_name}}}:\\
 these are just 2 missing tests to check whether giving a file a custom name even works.

2. fixes:
 a. ignored custom filename before setting {{{Content-Length}}} and changed the following condition a bit to fix 1.a. and the error case of 1.c.
 b. added a {{{self._default_content_type}}} flag to {{{HttpResponseBase.__init__()}}} to mark that there was no {{{content_type}}} explicitly set, so it should be figured out from the file, if possible, to fix 1.b.
 c. 
  * added a way to tell the filelike object's size if it's neither a file nor has a {{{getbuffer}}} attribute, using {{{.seek()}}} and {{{.tell()}}} if they're available, and otherwise {{{.read()}}}
  * moved {{{os.path.getsize}}} path to be the worst-case-scenario, to avoid reading the same file from disk again when possible
  * that fixes the remaining problem found in 1.c..
 d. moved {{{encoding_map}}} to initialize only when it's necessary.
 e. changed {{{set_headers()}}} to {{{_set_headers()}}} to mark it as an internal function.
 f. simplified the - IMO - unnecessarily detailed docs of FileResponse to just tell the user what do the parameters cause, instead of (almost) explaining what each line of code does - if the user wants to know which headers get what kind of values under which conditions they can just check the code, Python is nearly pseudocode anyway.

One thing i'm not sure about is if FileResponse should support reading filelikes from a different position than the beginning. If so, getting {{{Content-Length}}} would require a tiny change to accomodate a non-zero starting point, while otherwise it could use a {{{filelike.seek(0)}}} somewhere to be sure we're reading it from the very beginning."	Cleanup/optimization	closed	HTTP handling	dev	Normal	fixed	FileResponse	Carlton Gibson	Ready for checkin	1	0	0	0	0	0