[GSoC PATCH 1/2] userdiff: add builtin driver for gitconfig syntax

[Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>]

From Documentation/config.adoc:

"""
The file consists of sections and variables. A section begins with
the name of the section in square brackets and continues until the next
section begins. Section names are case-insensitive. Only alphanumeric
characters, `-` and `.` are allowed in section names. Each variable
must belong to some section, which means that there must be a section
header before the first setting of a variable.

[...]

Subsection names are case sensitive and can contain any characters except
newline and the null byte.

The variable names are case-insensitive, allow only alphanumeric characters
and `-`, and must start with an alphabetic character.
"""

Then, add a new builtin driver for gitconfig files, where:

- the funcname regular expression matches sections and subsections,
  i. e. the pattern [SECTION] or [SECTION "SUBSECTION"], where the
  section is composed by alphanumeric numbers, `-` and `.`, and
  subsection names may be composed by any characters;

- word_regex is more permissive, matching any word with one or more
  non-whitespace characters.

Signed-off-by: Lucas Seiki Oshiro <lucasseikioshiro@gmail.com>
---
 userdiff.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/userdiff.c b/userdiff.c
index 340c4eb4f7..5bbcc2b690 100644
--- a/userdiff.c
+++ b/userdiff.c
@@ -198,6 +198,10 @@ IPATTERN("fountain",
 	 "^((\\.[^.]|(int|ext|est|int\\.?/ext|i/e)[. ]).*)$",
 	 /* -- */
 	 "[^ \t-]+"),
+PATTERNS("gitconfig",
+         "^\\[[a-zA-Z0-9]+\\]|\\[[a-zA-Z0-9]+[ \t]+\".+\"\\]$",
+         /* -- */
+         "[^ \t]+"),
 PATTERNS("golang",
 	 /* Functions */
 	 "^[ \t]*(func[ \t]*.*(\\{[ \t]*)?)\n"
-- 
2.39.5 (Apple Git-154)