Move the comment about termination logic where it belongs

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

diff --git a/strace.c b/strace.c
index 35089abe0c7e17be715faddf7d700697f70871a6..513d7cf486b388c90868ad36f1e61137d86c4f84 100644 (file)
--- a/strace.c
+++ b/strace.c
@@ -2043,8 +2043,26 @@ trace(void)
        if (interrupted)
                return false;
 
-       if (popen_pid != 0 && nprocs == 0)
-               return false;
+       /*
+        * Used to exit simply when nprocs hits zero, but in this testcase:
+        *  int main() { _exit(!!fork()); }
+        * under strace -f, parent sometimes (rarely) manages
+        * to exit before we see the first stop of the child,
+        * and we are losing track of it:
+        *  19923 clone(...) = 19924
+        *  19923 exit_group(1)     = ?
+        *  19923 +++ exited with 1 +++
+        * Exiting only when wait() returns ECHILD works better.
+        */
+       if (popen_pid != 0) {
+               /* However, if -o|logger is in use, we can't do that.
+                * Can work around that by double-forking the logger,
+                * but that loses the ability to wait for its completion
+                * on exit. Oh well...
+                */
+               if (nprocs == 0)
+                       return false;
+       }
 
        if (interactive)
                sigprocmask(SIG_SETMASK, &empty_set, NULL);
@@ -2269,23 +2287,6 @@ main(int argc, char *argv[])
 {
        init(argc, argv);
 
-       /*
-        * Run main tracing loop.
-        *
-        * Used to be "while (nprocs != 0)", but in this testcase:
-        *  int main() { _exit(!!fork()); }
-        * under strace -f, parent sometimes (rarely) manages
-        * to exit before we see the first stop of the child,
-        * and we are losing track of it:
-        *  19923 clone(...) = 19924
-        *  19923 exit_group(1)     = ?
-        *  19923 +++ exited with 1 +++
-        * Waiting for ECHILD works better.
-        * (However, if -o|logger is in use, we can't do that.
-        * Can work around that by double-forking the logger,
-        * but that loses the ability to wait for its completion on exit.
-        * Oh well...)
-        */
        while (trace())
                ;