Revert "terminal_give_to_job() was bypassing the cont branch"

This reverts commit b27217e106.
It was meant for the major branch.

src/proc.cpp

@@ -789,8 +789,6 @@ bool terminal_give_to_job(job_t *j, int cont) {
         return true;
     }
 
-    signal_block(true);
-
     //Previously, terminal_give_to_job was being called for each process in a job, hence all the comments
     //and warnings below. It is now only called for the first process in a job.t d
 
@@ -803,10 +801,11 @@ bool terminal_give_to_job(job_t *j, int cont) {
     //for SIGTTOU are installed. Read: http://curiousthing.org/sigttin-sigttou-deep-dive-linux
     //In all cases, our goal here was just to hand over control of the terminal to this process group,
     //which is a no-op if it's already been done.
-    if (tcgetpgrp(STDIN_FILENO) == j->pgid) {
+    auto previous_owner = tcgetpgrp(STDIN_FILENO);
+    if (previous_owner == j->pgid) {
         debug(2, L"Process group %d already has control of terminal\n", j->pgid);
+        return true;
     }
-    else {
     debug(4, L"Attempting bring process group to foreground via tcsetpgrp for job->pgid %d\n", j->pgid);
     debug(4, L"caller session id: %d, pgid %d has session id: %d\n", getsid(0), j->pgid, getsid(j->pgid));
 
@@ -819,35 +818,19 @@ bool terminal_give_to_job(job_t *j, int cont) {
     //thing is that we can guarantee the process isn't going to exit while we wait (which would cause us to
     //possibly block indefinitely).
 
-        while (tcsetpgrp(STDIN_FILENO, j->pgid) != 0) {
+    signal_block(true);
-            if (errno == EINTR) {
+    int result = -1;
-                //always retry on EINTR
+    errno = EINTR;
+    while (result == -1 && (errno == EINTR || errno == EPERM)) {
+        result = tcsetpgrp(STDIN_FILENO, j->pgid);
     }
-            else if (errno == EPERM) {
+    if (result == -1) {
-                //so long as this isn't because the process group is dead
-                int wait_result = waitpid(-1 * j->pgid, &wait_result, WNOHANG);
-                if (wait_result == -1) {
-                    //everyone in the process group has exited
-                    //The only way that can happen is if the very last process in the group terminated, and didn't need
-                    //to access the terminal, otherwise it would have hung waiting for terminal IO. We can ignore this.
-                    //Note that -1 is technically an "error" for waitpid in the sense that an invalid argument was specified
-                    //because no such process group exists any longer.
-                    //a "success" result would mean processes from the group still exist but is still running in some state
-                    //or the other.
-                    debug(3, L"terminal_give_to_job(): tcsetpgrp called but process group %d has terminated.\n", j->pgid);
-                    break;
-                }
-                debug(2, L"terminal_give_to_job(): EPERM.\n", j->pgid);
-            }
-            else {
         if (errno == ENOTTY) redirect_tty_output();
         debug(1, _(L"terminal_give_to_job(): Could not send job %d ('%ls') with pgid %d to foreground"), j->job_id, j->command_wcstr(), j->pgid);
         wperror(L"tcsetpgrp");
         signal_unblock(true);
         return false;
     }
-        }
-    }
 
     if (cont) {
         int result = -1;