ash: changes to ctrl-c handling

Make ctrl-c handling more like Unix.  Remove the hSIGINT event and the
code in waitpid_child() to catch it.  Add a call to raise_interrupt()
in ctrl_handler().

Prior to these changes interrupts in a child shell weren't properly
handled.  In release FRP-3466-g53c09d0e1 interrupting a sleep in a
child shell results in both shells competing for input:

   ~ $ sh
   ~ $ sleep 10
   ^C^C

   ~ $ ~ $ pwd
   sh: w: not found
   ~ $
   sh: pd: not found
   ~ $

With recent changes:

   ~ $ sh
   ~ $ sleep 10
   ^C
   ~ $ echo $?
   130
   ~ $ exit
   ^C
   ~ $ echo $?
   130
   ~ $

The error return from the parent shell is due to the lack of job
control.  Upstream BusyBox ash and dash both do the same when job
control is disabled.

1 files changed, 13 insertions, 57 deletions

diff --git a/shell/ash.c b/shell/ash.c
index f11449530..decd6c0f7 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -771,6 +771,10 @@ raise_interrupt(void)
                 signal(SIGINT, SIG_DFL);
                 raise(SIGINT);
         }
+#if ENABLE_PLATFORM_MINGW32
+        if (iflag)
+                write(STDOUT_FILENO, "^C", 2);
+#endif
         /* bash: ^C even on empty command line sets $? */
         exitstatus = SIGINT + 128;
         raise_exception(EXINT);
@@ -4656,14 +4660,12 @@ sprint_status48(char *os, int status, int sigonly)
 }
 
 #if ENABLE_PLATFORM_MINGW32
-
-HANDLE hSIGINT;         /* Ctrl-C is pressed */
-
 static BOOL WINAPI ctrl_handler(DWORD dwCtrlType)
 {
         if (dwCtrlType == CTRL_C_EVENT || dwCtrlType == CTRL_BREAK_EVENT) {
+                if (!suppress_int)
+                        raise_interrupt(); /* does not return */
                 pending_int = 1;
-                SetEvent(hSIGINT);
                 return TRUE;
         }
         return FALSE;
@@ -4683,21 +4685,19 @@ waitpid_child(int *status, int wait_flags)
         HANDLE *proclist;
         pid_t pid = -1;
         DWORD win_status, idx;
-        int i, delay;
+        int i;
 
         for (jb = curjob; jb; jb = jb->prev_job) {
                 if (jb->state != JOBDONE)
                         pid_nr += jb->nprocs;
         }
-        if ( pid_nr++ == 0 )
+        if (pid_nr == 0)
                 return -1;
 
         pidlist = ckmalloc(sizeof(*pidlist)*pid_nr);
         proclist = ckmalloc(sizeof(*proclist)*pid_nr);
 
-        pidlist[0] = -1;
-        proclist[0] = hSIGINT;
-        pid_nr = 1;
+        pid_nr = 0;
         for (jb = curjob; jb; jb = jb->prev_job) {
                 if (jb->state == JOBDONE)
                         continue;
@@ -4710,56 +4710,15 @@ waitpid_child(int *status, int wait_flags)
                 }
         }
 
-        if (pid_nr == 1)
+        if (pid_nr == 0)
                 goto done;
 
         idx = WaitForMultipleObjects(pid_nr, proclist, FALSE,
                                 wait_flags&WNOHANG ? 1 : INFINITE);
         if (idx < pid_nr) {
-                if (idx == 0) {         /* hSIGINT */
-                        ResetEvent(hSIGINT);
-
-                        ps = curjob->ps;
-                        for (i = 0; i < curjob->nprocs; ++i) {
-                                if (ps[i].ps_proc) {
-                                        kill_SIGTERM_by_handle(ps[i].ps_proc, 128+SIGINT);
-                                        pid = ps[i].ps_pid;     /* remember last valid pid */
-                                }
-                        }
-
-                        Sleep(200);
-                        delay = FALSE;
-                        for (i = 0; i < curjob->nprocs; ++i) {
-                                DWORD code;
-                                if (ps[i].ps_proc &&
-                                                GetExitCodeProcess(ps[i].ps_proc, &code) &&
-                                                code == STILL_ACTIVE) {
-                                        TerminateProcess(ps[i].ps_proc, 128+SIGINT);
-                                        delay = TRUE;
-                                }
-                        }
-
-                        if (delay)
-                                Sleep(200);
-                        for (i = 0; i < curjob->nprocs; ++i) {
-                                /* mark all pids dead except the one we'll return */
-                                if (ps[i].ps_pid != pid) {
-                                        ps[i].ps_status = 128 + SIGINT;
-                                        ps[i].ps_pid = -1;
-                                        CloseHandle(ps[i].ps_proc);
-                                        ps[i].ps_proc = NULL;
-                                }
-                        }
-
-                        *status = 128 + SIGINT; /* terminated by a signal */
-                        if (iflag)
-                                write(STDOUT_FILENO, "^C", 2);
-                }
-                else {          /* valid pid index */
-                        GetExitCodeProcess(proclist[idx], &win_status);
-                        *status = (int)win_status << 8;
-                        pid = pidlist[idx];
-                }
+                GetExitCodeProcess(proclist[idx], &win_status);
+                *status = (int)win_status << 8;
+                pid = pidlist[idx];
         }
  done:
         free(pidlist);
@@ -14821,7 +14780,6 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
         if ((uintptr_t)r == 2) {
                 /* ^C pressed, propagate event */
                 if (iflag) {
-                        write(STDOUT_FILENO, "^C", 2);
                         raise_interrupt();
                 }
                 else {
@@ -15269,8 +15227,6 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
         basepf.next_to_pgetc = basepf.buf = ckmalloc(IBUFSIZ);
         basepf.linno = 1;
 
-        hSIGINT = CreateEvent(NULL, TRUE, FALSE, NULL);
-
         if (argc == 3 && !strcmp(argv[1], "--fs")) {
                 forkshell_init(argv[2]);
                 /* only reached in case of error */