Introduce i18n.commitencoding.

This is to hold what the project-local rule as to the
charset/encoding for the commit log message is.  Lack of it
defaults to utf-8.

Signed-off-by: Junio C Hamano <junkio@cox.net>

cache.h

@@ -399,6 +399,9 @@ extern int check_repository_format_version(const char *var, const char *value);
 extern char git_default_email[MAX_GITNAME];
 extern char git_default_name[MAX_GITNAME];
 
+#define MAX_ENCODING_LENGTH 64
+extern char git_commit_encoding[MAX_ENCODING_LENGTH];
+
 /* Sane ctype - no locale, and works with signed chars */
 #undef isspace
 #undef isdigit

config.c

@@ -237,6 +237,11 @@ int git_default_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "i18n.commitencoding")) {
+		strncpy(git_commit_encoding, value, sizeof(git_commit_encoding));
+		return 0;
+	}
+
 	/* Add other config variables here.. */
 	return 0;
 }

environment.c

@@ -14,6 +14,7 @@ char git_default_name[MAX_GITNAME];
 int trust_executable_bit = 1;
 int only_use_symrefs = 0;
 int repository_format_version = 0;
+char git_commit_encoding[MAX_ENCODING_LENGTH] = "utf-8";
 
 static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,
 	*git_graft_file;