notcurses_stop: restore nonblocking state #1090

src/lib/fd.c

@@ -79,15 +79,25 @@ ncfdplane_thread(void* vncfp){
   return NULL;
 }
 
-int set_fd_nonblocking(int fd){
+int set_fd_nonblocking(int fd, unsigned state, unsigned* oldstate){
   int flags = fcntl(fd, F_GETFL, 0);
   if(flags < 0){
     return -1;
   }
-  if(flags & O_NONBLOCK){
-    return 0;
+  if(oldstate){
+    *oldstate = flags & O_NONBLOCK;
+  }
+  if(state){
+    if(flags & O_NONBLOCK){
+      return 0;
+    }
+    flags |= O_NONBLOCK;
+  }else{
+    if(!(flags & O_NONBLOCK)){
+      return 0;
+    }
+    flags &= ~O_NONBLOCK;
   }
-  flags |= O_NONBLOCK;
   if(fcntl(fd, F_SETFL, flags)){
     return -1;
   }
@@ -188,7 +198,7 @@ launch_pipe_process(int* pipe, int* pidfd){
     }
   }else if(p > 0){ // parent
     *pipe = pipes[0];
-    set_fd_nonblocking(*pipe);
+    set_fd_nonblocking(*pipe, 1, NULL);
   }
   return p;
 }

src/lib/internal.h

@@ -373,6 +373,7 @@ typedef struct notcurses {
   int loglevel;
   palette256 palette; // 256-indexed palette can be used instead of/with RGB
   bool palette_damage[NCPALETTESIZE];
+  unsigned stdio_blocking_save; // was stdio blocking at entry? restore on stop.
 } notcurses;
 
 #include "blitset.h"
@@ -1152,7 +1153,7 @@ int ncinputlayer_init(ncinputlayer* nilayer, FILE* infp);
 // FIXME absorb into ncinputlayer_init()
 int cbreak_mode(int ttyfd, const struct termios* tpreserved);
 
-int set_fd_nonblocking(int fd);
+int set_fd_nonblocking(int fd, unsigned state, unsigned* oldstate);
 
 // Given the four channels arguments, verify that:
 //

src/lib/notcurses.c

@@ -777,6 +777,7 @@ void notcurses_stats_reset(notcurses* nc, ncstats* stats){
 // the environment / terminal definition.
 static void
 init_banner_warnings(const notcurses* nc, FILE* out){
+  // might be using stderr, so don't just reuse stdout decision
   const bool tty = isatty(fileno(out));
   if(tty){
     term_fg_palindex(nc, out, nc->tcache.colors <= 88 ? 1 % nc->tcache.colors : 0xcb);
@@ -1064,7 +1065,7 @@ notcurses* notcurses_core_init(const notcurses_options* opts, FILE* outfp){
   if(ncinputlayer_init(&ret->input, stdin)){
     goto err;
   }
-  if(set_fd_nonblocking(ret->input.ttyinfd)){
+  if(set_fd_nonblocking(ret->input.ttyinfd, 1, &ret->stdio_blocking_save)){
     goto err;
   }
   // Neither of these is supported on e.g. the "linux" virtual console.
@@ -1168,6 +1169,7 @@ int notcurses_stop(notcurses* nc){
   int ret = 0;
   if(nc){
     ret |= notcurses_stop_minimal(nc);
+    ret |= set_fd_nonblocking(nc->input.ttyinfd, nc->stdio_blocking_save, NULL);
     if(nc->stdplane){
       notcurses_drop_planes(nc);
       free_plane(nc->stdplane);