Merge branch 'jk/pager-swap'

* jk/pager-swap:
  spawn pager via run_command interface
  run-command: add pre-exec callback

pager.c

@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "run-command.h"
 
 /*
  * This is split up from the rest of git so that we can do
@@ -8,7 +9,7 @@
 static int spawned_pager;
 
 #ifndef __MINGW32__
-static void run_pager(const char *pager)
+static void pager_preexec(void)
 {
 	/*
 	 * Work around bug in "less" by not starting it until we
@@ -20,17 +21,13 @@ static void run_pager(const char *pager)
 	FD_SET(0, &in);
 	select(1, &in, NULL, &in, NULL);
 
-	execlp(pager, pager, NULL);
-	execl("/bin/sh", "sh", "-c", pager, NULL);
+	setenv("LESS", "FRSX", 0);
 }
-#else
-#include "run-command.h"
+#endif
 
 static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
-static struct child_process pager_process = {
-	.argv = pager_argv,
-	.in = -1
-};
+static struct child_process pager_process;
+
 static void wait_for_pager(void)
 {
 	fflush(stdout);
@@ -40,14 +37,9 @@ static void wait_for_pager(void)
 	close(2);
 	finish_command(&pager_process);
 }
-#endif
 
 void setup_pager(void)
 {
-#ifndef __MINGW32__
-	pid_t pid;
-	int fd[2];
-#endif
 	const char *pager = getenv("GIT_PAGER");
 
 	if (!isatty(1))
@@ -66,37 +58,13 @@ void setup_pager(void)
 
 	spawned_pager = 1; /* means we are emitting to terminal */
 
-#ifndef __MINGW32__
-	if (pipe(fd) < 0)
-		return;
-	pid = fork();
-	if (pid < 0) {
-		close(fd[0]);
-		close(fd[1]);
-		return;
-	}
-
-	/* return in the child */
-	if (!pid) {
-		dup2(fd[1], 1);
-		dup2(fd[1], 2);
-		close(fd[0]);
-		close(fd[1]);
-		return;
-	}
-
-	/* The original process turns into the PAGER */
-	dup2(fd[0], 0);
-	close(fd[0]);
-	close(fd[1]);
-
-	setenv("LESS", "FRSX", 0);
-	run_pager(pager);
-	die("unable to execute pager '%s'", pager);
-	exit(255);
-#else
 	/* spawn the pager */
 	pager_argv[2] = pager;
+	pager_process.argv = pager_argv;
+	pager_process.in = -1;
+#ifndef __MINGW32__
+	pager_process.preexec_cb = pager_preexec;
+#endif
 	if (start_command(&pager_process))
 		return;
 
@@ -107,7 +75,6 @@ void setup_pager(void)
 
 	/* this makes sure that the parent terminates after the pager */
 	atexit(wait_for_pager);
-#endif
 }
 
 int pager_in_use(void)

run-command.c

@@ -111,6 +111,8 @@ int start_command(struct child_process *cmd)
 					unsetenv(*cmd->env);
 			}
 		}
+		if (cmd->preexec_cb)
+			cmd->preexec_cb();
 		if (cmd->git_cmd) {
 			execv_git_cmd(cmd->argv);
 		} else {

run-command.h

@@ -42,6 +42,7 @@ struct child_process {
 	unsigned no_stderr:1;
 	unsigned git_cmd:1; /* if this is to be git sub-command */
 	unsigned stdout_to_stderr:1;
+	void (*preexec_cb)(void);
 };
 
 int start_command(struct child_process *);