Comments not preserved on merge

[Tom Keffer]

Using ConfigObj v5.0.6, consider this:

import sys
from StringIO import StringIO
from configobj import ConfigObj

c = ConfigObj(StringIO("""[Section1]"""))

d = ConfigObj(StringIO("""[Section1]

  # This is a Section2 comment
  [[Section2]]
     option2 = foo
"""))

c.merge(d)

c.write(sys.stdout)

The output is:

[Section1]
[[Section2]]
option2 = foo

while I would have expected

[Section1]
# This is a Section2 comment
[[Section2]]
option2 = foo

[Irina Truong]

+1, we have this issue in pgcli: dbcli/pgcli#1240.

[Rob Dennis]

makes sense and thanks for the MR; adding to 5.1.0 milestone

[Tom Keffer]

I should add that parentage is also not preserved on merge. This is what we do to get around these V5 limitations:

from configobj import Section

def merge_config(self_config, indict):
    """Merge and patch a config file"""

    # Do a ConfigObj merge:
    self_config.merge(indict)
    # Then fix comments and parentage:
    patch_config(self_config, indict)


def patch_config(self_config, indict):
    """The ConfigObj merge does not transfer over parentage, nor comments. This function
    fixes these limitations.
    """
    for key in self_config:
        if isinstance(self_config[key], Section) \
                and key in indict and isinstance(indict[key], Section):
            self_config[key].parent = self_config
            self_config[key].main = self_config.main
            self_config.comments[key] = indict.comments[key]
            self_config.inline_comments[key] = indict.inline_comments[key]
            patch_config(self_config[key], indict[key])