diff options
Diffstat (limited to 'src/process.c')
| -rw-r--r-- | src/process.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/src/process.c b/src/process.c index 2ec10b12ecc..496b1f2b70c 100644 --- a/src/process.c +++ b/src/process.c @@ -5006,6 +5006,7 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd, struct timespec got_output_end_time = invalid_timespec (); enum { MINIMUM = -1, TIMEOUT, INFINITY } wait; int got_some_output = -1; + uintmax_t prev_wait_proc_nbytes_read = wait_proc ? wait_proc->nbytes_read : 0; #if defined HAVE_GETADDRINFO_A || defined HAVE_GNUTLS bool retry_for_async; #endif @@ -5460,6 +5461,8 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd, if (nfds == 0) { /* Exit the main loop if we've passed the requested timeout, + or have read some bytes from our wait_proc (either directly + in this call or indirectly through timers / process filters), or aren't skipping processes and got some output and haven't lowered our timeout due to timers or SIGIO and have waited a long amount of time due to repeated @@ -5467,7 +5470,9 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd, struct timespec huge_timespec = make_timespec (TYPE_MAXIMUM (time_t), 2 * TIMESPEC_RESOLUTION); struct timespec cmp_time = huge_timespec; - if (wait < TIMEOUT) + if (wait < TIMEOUT + || (wait_proc + && wait_proc->nbytes_read != prev_wait_proc_nbytes_read)) break; if (wait == TIMEOUT) cmp_time = end_time; @@ -5772,6 +5777,15 @@ wait_reading_process_output (intmax_t time_limit, int nsecs, int read_kbd, maybe_quit (); } + /* Timers and/or process filters that we have run could have themselves called + `accept-process-output' (and by that indirectly this function), thus + possibly reading some (or all) output of wait_proc without us noticing it. + This could potentially lead to an endless wait (dealt with earlier in the + function) and/or a wrong return value (dealt with here). */ + if (wait_proc && wait_proc->nbytes_read != prev_wait_proc_nbytes_read) + got_some_output = min (INT_MAX, (wait_proc->nbytes_read + - prev_wait_proc_nbytes_read)); + return got_some_output; } @@ -5890,6 +5904,9 @@ read_process_output (Lisp_Object proc, int channel) coding->mode |= CODING_MODE_LAST_BLOCK; } + /* Ignore carryover, it's been added by a previous iteration already. */ + p->nbytes_read += nbytes; + /* Now set NBYTES how many bytes we must decode. */ nbytes += carryover; |