File tcsh-6.16.00-grabpgrp.dif of Package tcsh

--- sh.c
+++ sh.c	25 Feb 2009 22:53:47 -0000
@@ -1103,17 +1103,7 @@
 	    }
 #endif /* NeXT */
 #ifdef BSDJOBS			/* if we have tty job control */
-    retry:
-	    if ((tpgrp = tcgetpgrp(f)) != -1) {
-		if (tpgrp != shpgrp) {
-		    struct sigaction old;
-
-		    sigaction(SIGTTIN, NULL, &old);
-		    signal(SIGTTIN, SIG_DFL);
-		    (void) kill(0, SIGTTIN);
-		    sigaction(SIGTTIN, &old, NULL);
-		    goto retry;
-		}
+	    if (grabpgrp(f, shpgrp) != -1) {
 		/*
 		 * Thanks to Matt Day for the POSIX references, and to
 		 * Paul Close for the SGI clarification.
@@ -2356,3 +2346,28 @@
 	rechist(NULL, adrof(STRsavehist) != NULL);
     }
 }
+
+/*
+ * Grab the tty repeatedly, and give up if we are not in the correct
+ * tty process group.
+ */
+int
+grabpgrp(int fd, pid_t desired)
+{
+    struct sigaction old;
+    pid_t pgrp;
+    size_t i;
+
+    for (i = 0; i < 100; i++) {
+	if ((pgrp = tcgetpgrp(fd)) == -1)
+	    return -1;
+	if (pgrp == desired)
+	    return 0;
+	(void)sigaction(SIGTTIN, NULL, &old);
+	(void)signal(SIGTTIN, SIG_DFL);
+	(void)kill(0, SIGTTIN);
+	(void)sigaction(SIGTTIN, &old, NULL);
+    }
+    errno = EPERM;
+    return -1;
+}
--- sh.decls.h
+++ sh.decls.h	25 Feb 2009 22:53:47 -0000
@@ -52,6 +52,7 @@
 #else
 extern	void		  xexit		(int);
 #endif
+extern	int		  grabpgrp	(int, pid_t);
 
 /*
  * sh.dir.c
--- sh.func.c
+++ sh.func.c	25 Feb 2009 22:53:47 -0000
@@ -2272,10 +2272,9 @@
 dosuspend(Char **v, struct command *c)
 {
 #ifdef BSDJOBS
-    int     ctpgrp;
     struct sigaction old;
 #endif /* BSDJOBS */
-    
+
     USE(c);
     USE(v);
 
@@ -2295,17 +2294,8 @@
 
 #ifdef BSDJOBS
     if (tpgrp != -1) {
-retry:
-	ctpgrp = tcgetpgrp(FSHTTY);
-	if (ctpgrp == -1)
+	if (grabpgrp(FSHTTY, opgrp) == -1)
 	    stderror(ERR_SYSTEM, "tcgetpgrp", strerror(errno));
-	if (ctpgrp != opgrp) {
-	    sigaction(SIGTTIN, NULL, &old);
-	    signal(SIGTTIN, SIG_DFL);
-	    (void) kill(0, SIGTTIN);
-	    sigaction(SIGTTIN, &old, NULL);
-	    goto retry;
-	}
 	(void) setpgid(0, shpgrp);
 	(void) tcsetpgrp(FSHTTY, shpgrp);
     }