git-var: constness and globalness cleanup.

var.c::git_var read function did not have to return writable
strings; make it and the functions it points at return const char *
instead.

ident.c::get_ident() did not need to be global, so make it
static.

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

cache.h

@@ -263,9 +263,8 @@ void datestamp(char *buf, int bufsize);
 unsigned long approxidate(const char *);
 
 extern int setup_ident(void);
-extern char *get_ident(const char *name, const char *email, const char *date_str);
-extern char *git_author_info(void);
-extern char *git_committer_info(void);
+extern const char *git_author_info(void);
+extern const char *git_committer_info(void);
 
 static inline void *xmalloc(size_t size)
 {

ident.c

@@ -156,7 +156,8 @@ static int copy(char *buf, int size, int offset, const char *src)
 	return offset;
 }
 
-char *get_ident(const char *name, const char *email, const char *date_str)
+static const char *get_ident(const char *name, const char *email,
+			     const char *date_str)
 {
 	static char buffer[1000];
 	char date[50];
@@ -181,12 +182,16 @@ char *get_ident(const char *name, const char *email, const char *date_str)
 	return buffer;
 }
 
-char *git_author_info(void)
+const char *git_author_info(void)
 {
-	return get_ident(getenv("GIT_AUTHOR_NAME"), getenv("GIT_AUTHOR_EMAIL"), getenv("GIT_AUTHOR_DATE"));
+	return get_ident(getenv("GIT_AUTHOR_NAME"),
+			 getenv("GIT_AUTHOR_EMAIL"),
+			 getenv("GIT_AUTHOR_DATE"));
 }
 
-char *git_committer_info(void)
+const char *git_committer_info(void)
 {
-	return get_ident(getenv("GIT_COMMITTER_NAME"), getenv("GIT_COMMITTER_EMAIL"), getenv("GIT_COMMITTER_DATE"));
+	return get_ident(getenv("GIT_COMMITTER_NAME"),
+			 getenv("GIT_COMMITTER_EMAIL"),
+			 getenv("GIT_COMMITTER_DATE"));
 }

var.c

@@ -12,7 +12,7 @@ static const char var_usage[] = "git-var [-l | <variable>]";
 
 struct git_var {
 	const char *name;
-	char *(*read)(void);
+	const char *(*read)(void);
 };
 static struct git_var git_vars[] = {
 	{ "GIT_COMMITTER_IDENT", git_committer_info },