[nkbeast]

git config joins an unquoted value that ends in a backslash with the next line: the backslash and the newline are removed and the next line is appended verbatim. Reproducing with git itself:

$ printf '[a]\n\tk = line1\\\n line2\n' > g.cfg
$ git config -f g.cfg a.k
line1 line2

GitPython only implemented multi-line values for quoted strings. For unquoted values the continuation line was silently dropped — GitConfigParser read back line1\ and the line2 content vanished, truncating whatever the user had stored (aliases, hook commands, any hand-edited multi-line value).

The fix reads the continuation inside _read and joins it, chaining across lines that themselves end in a backslash, with the exact rules git uses:

• a single trailing backslash → continuation, next line appended verbatim (leading whitespace included)
• an even number of trailing backslashes → an escaped one, value ends there (val\\\\ stays val\\\\)
• a lone backslash right at end-of-file → dropped

All five cases are asserted against git's own output in the new test.