[git commit] ash: ^C with SIG_INGed SIGINT should not exit the shell

[Denys Vlasenko]

commit: https://git.busybox.net/busybox/commit/?id=68b402ee51f12f8c3b11638b042f57e025359faf
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

function                                             old     new   delta
__pgetc                                              501     522     +21

Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 loginutils/login.c   | 4 +++-
 loginutils/sulogin.c | 5 +++++
 shell/ash.c          | 8 +++++++-
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/loginutils/login.c b/loginutils/login.c
index 569053c12..cac4349b2 100644
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -608,7 +608,9 @@ int login_main(int argc UNUSED_PARAM, char **argv)
 	 * But without this, bash 3.0 will not enable ctrl-c either.
 	 * Maybe bash is buggy?
 	 * Need to find out what standards say about /bin/login -
-	 * should we leave SIGINT etc enabled or disabled? */
+	 * should we leave SIGINT etc enabled or disabled?
+	 * Also note: sulogin does not do it! Why?
+	 */
 	signal(SIGINT, SIG_DFL);
 
 	/* Exec login shell with no additional parameters */
diff --git a/loginutils/sulogin.c b/loginutils/sulogin.c
index 5f1c1178f..2f87c77c0 100644
--- a/loginutils/sulogin.c
+++ b/loginutils/sulogin.c
@@ -111,6 +111,11 @@ int sulogin_main(int argc UNUSED_PARAM, char **argv)
 		}
 	}
 
+	/*
+	 * Note: login does this (should we do it too?):
+	 */
+	/*signal(SIGINT, SIG_DFL);*/
+
 	/* Exec login shell with no additional parameters. Never returns. */
 	exec_login_shell(shell);
 }
diff --git a/shell/ash.c b/shell/ash.c
index 4c5dd1298..12b2db3a9 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -10784,18 +10784,24 @@ preadfd(void)
 		line_input_state->path_lookup = pathval();
 # endif
 		reinit_unicode_for_ash();
+ again:
 		nr = read_line_input(line_input_state, cmdedit_prompt, buf, IBUFSIZ);
 		if (nr == 0) {
 			/* ^C pressed, "convert" to SIGINT */
 			write(STDOUT_FILENO, "^C", 2);
 			raise(SIGINT);
+			/* raise(SIGINT) did not work! (e.g. if SIGINT
+			 * is SIG_INGed on startup, it stays SIG_IGNed)
+			 */
 			if (trap[SIGINT]) {
 				buf[0] = '\n';
 				buf[1] = '\0';
 				return 1;
 			}
 			exitstatus = 128 + SIGINT;
-			return -1;
+			/* bash behavior on ^C + ignored SIGINT: */
+			write(STDOUT_FILENO, "\n", 1);
+			goto again;
 		}
 		if (nr < 0) {
 			if (errno == 0) {