log: extract common part from getgraphlogrevs() and getlogrevs()

graphlog: remove useless check for empty repo when --follow is specified This prepares for extracting common part from getgraphlogrevs() and getlogrevs(). getlogrevs() does not handle empty repo specially. When it was added at d74099ac2ac1, revs were build by old-style query, '.:0'. So I think the purpose of "len(repo) > 0" was to handle the case of . = null. Currently it isn't necessary for 'reverse(:.)', and it does not work if repo is not empty but p1 is null. $ hg up null $ hg glog --follow -T '{rev}:{node|short}\n' o 0:0a04b987be5a The subsequent patch will fix this problem, so drops the wrong version for now.

graphlog: move comment and flag denoting revs might be unsorted This prepares for extracting common part from getgraphlogrevs() and getlogrevs(). "possiblyunsorted" exists only in getgraphlogrevs().

graphlog: remove too early return from getgraphlogrevs() for empty repo Even if repository is empty, null revision should exist.

trydiff: call util.binary in only one place It's practically free to call util.binary on empty or None content. By relying on that, we can replace the current four call sites by one.

trydiff: collect all lossiness checks in one place By having all the checks for lossiness in one place, it becomes much easier to get an overview of the conditions that lead to losedatafn() being called. It also makes it obvious that it can not be called multiple times for a single time (something that was rather tricky to determine before).

trydiff: replace 'binarydiff' variable by 'binary' variable It's not obvious, but every path in the 'if opts.git or losedatafn:' block will have checked whether the file is binary [1]. Let's assign the result of this check to a variable so we can simplify by checking 'binary and opts.git' in only one place instead of every place we currently assign to 'binarydiff'. [1] Except when deleting an empty file, but checking whether an empty string is binary is very cheap anyway.

trydiff: rename 'op' to make it more specific Rename the 'op' variable that can take values None/'copy'/'rename' to 'copyop' to make it a little more specific.

hgweb: replace implicit <tbody> with explicit <thead> where appropriate Some templates in paper style use <tbody> elements inside <table> to assign a class to "body" part of that table (in this case, to make rows striped). The problem is that the <tbody> is preceded by <tr> element, which browsers understand as an implicit start of table body, so the following exlicit <tbody> will actually be "nested", which is not valid. Since that first <tr> contains table headers, wrapping it in <thead> is both semantically correct and follows the advertised XHTML 1.1 doctype.

obsolete: drop the explicit seek to EOF after append mode open() posixfile now handles this.