evolve: refactor content-divergence resolution logic
> What is the case we are looking at?
This is about refactoring the part of content-div resolution logic where it
decides which cset should be relocated and where.
> What is a "topologicial common ancestors" vs a "greatest common ancestors"?
`tca` is an ancestor which we can decide/find by looking at the at graph
visually for e.g
```
c3(*) c4(*)
| |
c2(x) c1(x)
c5 | /
\ | /
c0
```
(c5 is the successor of c2 and c1)
now here,
`tca` of c3 and c4 is: c0
`gca` of c3 and c4 is: c5
> What is the new top-level logic/behavior that makes it better?
The old code had some unnecessary edge cases just because we were using `gca`,
since it can point to a revision that is not a topological ancestor.
For e.g see b779b40f996e
Eventually, the code around this was getting messy unnecessarily. So I looked
into it and found a simple and more robust approach.
And in new code, it is simple and straightforward (and easy to understand),
where we handle the following 4 cases when solving content-div:
1) when both are on the same parent
=> (no need to do anything special, and simply proceed)
2) both are on the different parent but a) `tca` is the parent of one of them
or b) there is no non-obsolete revision between `tca` and one of the
divergent cset.
=> (relocate one to the other side and proceed)
3) both are on different parents and `tca` is not the parent of any of them and
there is at least one non-obsolete cset between tca and both the divergent
cset i.e (tca::div1) and (tca::div2) both the ranges have at least one non-obs
revision.
=> (this is the case which we don't handle yet, but the solution would be to
prompt the user to choose an evolve destination.)
4) both are in the parent-child relation
=> (both are merged and new cset will be based on the successor of `tca`)
Changes in test-evolve-issue5958.t demonstrate that new code also covered case4
because in a resolution of "two divergent csets with parent-child relation"
there should be one cset as a result and no orphan revs (as you can see there
was an orphan before this patch).
#!/usr/bin/env python
import re
import os
import os.path as op
import sys
INDEX = '''
Mercurial tests
===============
.. toctree::
:maxdepth: 1
'''
ignored_patterns = [
re.compile(r'^#if'),
re.compile(r'^#else'),
re.compile(r'^#endif'),
re.compile(r'#rest-ignore$'),
]
def rstify(orig, name):
newlines = []
code_block_mode = False
sphinx_directive_mode = False
for line in orig.splitlines():
# Emtpy lines doesn't change output
if not line:
newlines.append(line)
code_block_mode = False
sphinx_directive_mode = False
continue
ignored = False
for pattern in ignored_patterns:
if pattern.search(line):
ignored = True
break
if ignored:
continue
# Sphinx directives mode
if line.startswith(' .. '):
# Insert a empty line to makes sphinx happy
newlines.append("")
# And unindent the directive
line = line[2:]
sphinx_directive_mode = True
# Code mode
codeline = line.startswith(' ')
if codeline and not sphinx_directive_mode:
if code_block_mode is False:
newlines.extend(['::', ''])
code_block_mode = True
newlines.append(line)
return "\n".join(newlines)
def main(base):
if os.path.isdir(base):
one_dir(base)
else:
one_file(base)
def one_dir(base):
index = INDEX
# doc = lambda x: op.join(op.dirname(__file__), 'docs', x)
for fn in sorted(os.listdir(base)):
if not fn.endswith('.t'):
continue
name = os.path.splitext(fn)[0]
content = one_file(op.join(base, fn))
target = op.join(base, name + '.rst')
# with file(doc(name + '.rst'), 'w') as f:
with open(target, 'w') as f:
f.write(content)
index += '\n ' + name
# with file(doc('index.rst'), 'w') as f:
# f.write(index)
def one_file(path):
name = os.path.basename(path)[:-2]
return rstify(open(path).read(), name)
if __name__ == '__main__':
if len(sys.argv) != 2:
print('Please supply a path to tests dir as parameter')
sys.exit()
main(sys.argv[1])