"rebase -i": support special-purpose editor to edit insn sheet

diff --git a/pager.c b/pager.c
index 6b5c9e44b4ded338ddb344ae454d83a685b7569a..975955ba82a0dbb128d6733090cd74c2b509ea81 100644 (file)
--- a/pager.c
+++ b/pager.c
@@ -1,14 +1,18 @@
 #include "cache.h"
+#include "run-command.h"
+#include "sigchain.h"
+
+#ifndef DEFAULT_PAGER
+#define DEFAULT_PAGER "less"
+#endif
 
 /*
  * This is split up from the rest of git so that we can do
  * something different on Windows.
  */
 
-static int spawned_pager;
-
-#ifndef __MINGW32__
-static void run_pager(const char *pager)
+#ifndef WIN32
+static void pager_preexec(void)
 {
        /*
         * Work around bug in "less" by not starting it until we
@@ -19,18 +23,12 @@ static void run_pager(const char *pager)
        FD_ZERO(&in);
        FD_SET(0, &in);
        select(1, &in, NULL, &in, NULL);
-
-       execlp(pager, pager, NULL);
-       execl("/bin/sh", "sh", "-c", pager, NULL);
 }
-#else
-#include "run-command.h"
+#endif
+
+static const char *pager_argv[] = { NULL, NULL };
+static struct child_process pager_process;
 
-static const char *pager_argv[] = { "sh", "-c", NULL, NULL };
-static struct child_process pager_process = {
-       .argv = pager_argv,
-       .in = -1
-};
 static void wait_for_pager(void)
 {
        fflush(stdout);
@@ -40,18 +38,22 @@ static void wait_for_pager(void)
        close(2);
        finish_command(&pager_process);
 }
-#endif
 
-void setup_pager(void)
+static void wait_for_pager_signal(int signo)
 {
-#ifndef __MINGW32__
-       pid_t pid;
-       int fd[2];
-#endif
-       const char *pager = getenv("GIT_PAGER");
+       wait_for_pager();
+       sigchain_pop(signo);
+       raise(signo);
+}
 
-       if (!isatty(1))
-               return;
+const char *git_pager(int stdout_is_tty)
+{
+       const char *pager;
+
+       if (!stdout_is_tty)
+               return NULL;
+
+       pager = getenv("GIT_PAGER");
        if (!pager) {
                if (!pager_program)
                        git_config(git_default_config, NULL);
@@ -60,63 +62,51 @@ void setup_pager(void)
        if (!pager)
                pager = getenv("PAGER");
        if (!pager)
-               pager = "less";
+               pager = DEFAULT_PAGER;
        else if (!*pager || !strcmp(pager, "cat"))
-               return;
+               pager = NULL;
 
-       spawned_pager = 1; /* means we are emitting to terminal */
+       return pager;
+}
 
-#ifndef __MINGW32__
-       if (pipe(fd) < 0)
-               return;
-       pid = fork();
-       if (pid < 0) {
-               close(fd[0]);
-               close(fd[1]);
-               return;
-       }
+void setup_pager(void)
+{
+       const char *pager = git_pager(isatty(1));
 
-       /* return in the child */
-       if (!pid) {
-               dup2(fd[1], 1);
-               dup2(fd[1], 2);
-               close(fd[0]);
-               close(fd[1]);
+       if (!pager)
                return;
-       }
 
-       /* The original process turns into the PAGER */
-       dup2(fd[0], 0);
-       close(fd[0]);
-       close(fd[1]);
+       setenv("GIT_PAGER_IN_USE", "true", 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_argv[0] = pager;
+       pager_process.use_shell = 1;
+       pager_process.argv = pager_argv;
+       pager_process.in = -1;
+       if (!getenv("LESS")) {
+               static const char *env[] = { "LESS=FRSX", NULL };
+               pager_process.env = env;
+       }
+#ifndef WIN32
+       pager_process.preexec_cb = pager_preexec;
+#endif
        if (start_command(&pager_process))
                return;
 
        /* original process continues, but writes to the pipe */
        dup2(pager_process.in, 1);
-       dup2(pager_process.in, 2);
+       if (isatty(2))
+               dup2(pager_process.in, 2);
        close(pager_process.in);
 
        /* this makes sure that the parent terminates after the pager */
+       sigchain_push_common(wait_for_pager_signal);
        atexit(wait_for_pager);
-#endif
 }
 
 int pager_in_use(void)
 {
        const char *env;
-
-       if (spawned_pager)
-               return 1;
-
        env = getenv("GIT_PAGER_IN_USE");
        return env ? git_config_bool("GIT_PAGER_IN_USE", env) : 0;
 }