[PATCH 1/3] doc: grep: unify configuration variables definitions

[Matheus Tavares <matheus.bernardino@usp.br>]

The configuration variables for git-grep are duplicated in
"Documentation/git-grep.txt" and "Documentation/config/grep.txt", which
gqcan make maintenance difficult. The first also contains a definition
that is not present in the latter (grep.fullName), and the latter
received a wording improvement that was not replicated in the former:
see 91028f765 ("grep: clarify what `grep.patternType=default` means",
2021-12-05).

To avoid such problems, unify the information in one file and include it
in the other.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
---
 Documentation/config/grep.txt | 10 ++++++++--
 Documentation/git-grep.txt    | 37 ++++++-----------------------------
 2 files changed, 14 insertions(+), 33 deletions(-)

diff --git a/Documentation/config/grep.txt b/Documentation/config/grep.txt
index 182edd813a..6996e64574 100644
--- a/Documentation/config/grep.txt
+++ b/Documentation/config/grep.txt
@@ -17,8 +17,14 @@ grep.extendedRegexp::
 	other than 'default'.
 
 grep.threads::
-	Number of grep worker threads to use.
-	See `grep.threads` in linkgit:git-grep[1] for more information.
+	Number of grep worker threads to use. See `--threads`
+ifndef::git-grep[]
+	in linkgit:git-grep[1]
+endif::git-grep[]
+	for more information.
+
+grep.fullName::
+	If set to true, enable `--full-name` option by default.
 
 grep.fallbackToNoIndex::
 	If set to true, fall back to git grep --no-index if git grep
diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt
index 3d393fbac1..65a3ca1101 100644
--- a/Documentation/git-grep.txt
+++ b/Documentation/git-grep.txt
@@ -37,7 +37,6 @@ registered in the index file, or blobs in given tree objects.  Patterns
 are lists of one or more search expressions separated by newline
 characters.  An empty string as search expression matches all lines.
 
-
 OPTIONS
 -------
 --cached::
@@ -239,8 +238,10 @@ providing this option will cause it to die.
 	custom hunk-header' in linkgit:gitattributes[5]).
 
 --threads <num>::
-	Number of grep worker threads to use.
-	See `grep.threads` in 'CONFIGURATION' for more information.
+	Number of grep worker threads to use. If not provided (or set to
+	0), Git will use as many worker threads as the number of logical
+	cores available. The default value can also be set with the
+	`grep.threads` configuration.
 
 -f <file>::
 	Read patterns from <file>, one per line.
@@ -334,34 +335,8 @@ performance in this case, it might be desirable to use `--threads=1`.
 CONFIGURATION
 -------------
 
-grep.lineNumber::
-	If set to true, enable `-n` option by default.
-
-grep.column::
-	If set to true, enable the `--column` option by default.
-
-grep.patternType::
-	Set the default matching behavior. Using a value of 'basic', 'extended',
-	'fixed', or 'perl' will enable the `--basic-regexp`, `--extended-regexp`,
-	`--fixed-strings`, or `--perl-regexp` option accordingly, while the
-	value 'default' will return to the default matching behavior.
-
-grep.extendedRegexp::
-	If set to true, enable `--extended-regexp` option by default. This
-	option is ignored when the `grep.patternType` option is set to a value
-	other than 'default'.
-
-grep.threads::
-	Number of grep worker threads to use. If unset (or set to 0), Git will
-	use as many threads as the number of logical cores available.
-
-grep.fullName::
-	If set to true, enable `--full-name` option by default.
-
-grep.fallbackToNoIndex::
-	If set to true, fall back to git grep --no-index if git grep
-	is executed outside of a git repository.  Defaults to false.
-
+:git-grep: 1
+include::config/grep.txt[]
 
 GIT
 ---
-- 
2.37.0