pager: do not fork a pager if PAGER is set to empty.

This skips an extra pipe, and helps debugging tremendously.

[jc: PAGER=cat is a questionable hack and should be done as a separate
patch. ]

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/pager.c b/pager.c
index 1364e15d23527c0c4a11bcbe18c80c32af6d94b4..e5ba2738b681387495b840d39dfeca920c865616 100644 (file)
--- a/pager.c
+++ b/pager.c
@@ -5,22 +5,24 @@
  * something different on Windows, for example.
  */
 
-static void run_pager(void)
+static void run_pager(const char *pager)
 {
-       const char *prog = getenv("PAGER");
-       if (!prog)
-               prog = "less";
-       setenv("LESS", "-S", 0);
-       execlp(prog, prog, NULL);
+       execlp(pager, pager, NULL);
 }
 
 void setup_pager(void)
 {
        pid_t pid;
        int fd[2];
+       const char *pager = getenv("PAGER");
 
        if (!isatty(1))
                return;
+       if (!pager)
+               pager = "less";
+       else if (!*pager)
+               return;
+
        if (pipe(fd) < 0)
                return;
        pid = fork();
@@ -43,6 +45,7 @@ void setup_pager(void)
        close(fd[0]);
        close(fd[1]);
 
-       run_pager();
+       setenv("LESS", "-S", 0);
+       run_pager(pager);
        exit(255);
 }