templater: allow piping generator-type function output to filters
Template functions use "yield"s assuming that the result will be combined
into a string, which means both "f -> str" and "f -> generator" should behave
in the same way.
Before this patch, piping generator function resulted in a cryptic error.
We had to insert "|stringify" in this case.
$ hg log --template '{if(author, author)|user}\n'
abort: template filter 'userfilter' is not compatible with keyword
'[(<function runsymbol at 0x
7f5af2e8d8c0>, 'author'),
(<function runsymbol at 0x
7f5af2e8d8c0>, 'author')]'
#require unix-permissions no-root
$ hg init a
$ cd a
$ echo foo > b
$ hg add b
$ hg ci -m "b"
$ chmod -w .hg/store
$ cd ..
$ hg clone a b
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ chmod +w a/.hg/store # let test clean up
$ cd b
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
1 files, 1 changesets, 1 total revisions
$ cd ..