[PATCH] Support "valueless truth" in configuration parsing

[Junio C Hamano <gitster@pobox.com>]

With a configuration item somewhere (like ~/.gitconfig) like this:

    [sendemail]
        suppressfrom

"b4" barfs while parsing the configuration file.

The code assumes that "git config -z" output, after splitting at
NUL, would always be a LF separated variable and value, but that
does not hold for such a variable defined with only its name without
"= <value>", which means that variable is given the value "true".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 * It seems that this part of the parser hasn't changed at all since
   ae57d6ea (Initial commit after porting from korg-helpers,
   2020-03-14).  The patch was made against the current tip 47743a82
   (Improve tests exclusion from the built packages, 2024-07-17),
   but presumably it would apply anywhere.

 src/b4/__init__.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/b4/__init__.py b/src/b4/__init__.py
index 7164d3f..ae15b83 100644
--- a/src/b4/__init__.py
+++ b/src/b4/__init__.py
@@ -2824,7 +2824,10 @@ def get_config_from_git(regexp: str, defaults: Opti
     for line in out.split('\x00'):
         if not line:
             continue
-        key, value = line.split('\n', 1)
+        if '\n' in line:
+            key, value = line.split('\n', 1)
+        else:
+            key, value = line, 'true'
         try:
             chunks = key.split('.')
             cfgkey = chunks[-1].lower()