init: pipe detected terminal through to heuristics #1761

src/lib/input.c

@@ -1023,7 +1023,7 @@ pump_control_read(init_state* inits, unsigned char c){
 
 // complete the terminal detection process
 static int
-control_read(tinfo* tcache, int ttyfd){
+control_read(tinfo* tcache, int ttyfd, queried_terminals_e* detected){
   init_state inits = {
     .tcache = tcache,
     .state = STATE_NULL,
@@ -1032,6 +1032,7 @@ control_read(tinfo* tcache, int ttyfd){
   unsigned char* buf;
   ssize_t s;
 
+  *detected = TERMINAL_UNKNOWN;
   if((buf = malloc(BUFSIZ)) == NULL){
     return -1;
   }
@@ -1040,6 +1041,7 @@ control_read(tinfo* tcache, int ttyfd){
       int r = pump_control_read(&inits, buf[idx]);
       if(r == 1){ // success!
         free(buf);
+        *detected = inits.qterm;
 //fprintf(stderr, "at end, derived terminal %d\n", inits.qterm);
         return 0;
       }else if(r < 0){
@@ -1053,7 +1055,7 @@ err:
   return -1;
 }
 
-int ncinputlayer_init(tinfo* tcache, FILE* infp){
+int ncinputlayer_init(tinfo* tcache, FILE* infp, queried_terminals_e* detected){
   ncinputlayer* nilayer = &tcache->input;
   setbuffer(infp, NULL, 0);
   nilayer->inputescapes = NULL;
@@ -1068,7 +1070,7 @@ int ncinputlayer_init(tinfo* tcache, FILE* infp){
   nilayer->input_events = 0;
   int csifd = nilayer->ttyfd >= 0 ? nilayer->ttyfd : nilayer->infd;
   if(isatty(csifd)){
-    if(control_read(tcache, csifd)){
+    if(control_read(tcache, csifd, detected)){
       input_free_esctrie(&nilayer->inputescapes);
       return -1;
     }

src/lib/internal.h

@@ -1496,8 +1496,9 @@ cellcmp_and_dupfar(egcpool* dampool, nccell* damcell,
 // sets up the input layer, building a trie of escape sequences and their
 // nckey equivalents. if we are connected to a tty, this also completes the
 // terminal detection sequence (we ought have already written our initial
-// queries, ideally as early as possible).
-int ncinputlayer_init(tinfo* tcache, FILE* infp);
+// queries, ideally as early as possible). if we are able to determine the
+// terminal conclusively, it will be written to |detected|.
+int ncinputlayer_init(tinfo* tcache, FILE* infp, queried_terminals_e* detected);
 
 void ncinputlayer_stop(ncinputlayer* nilayer);
 

src/lib/termdesc.c

@@ -74,15 +74,31 @@ terminfostr(char** gseq, const char* name){
   return 0;
 }
 
+// we couldn't get a terminal from interrogation, so let's see if the TERM
+// matches any of our known terminals. this can only be as accurate as the
+// TERM setting is (and as up-to-date and complete as we are).
+static int
+match_termname(const char* termname, queried_terminals_e* qterm){
+  if(strstr(termname, "alacritty")){
+    *qterm = TERMINAL_ALACRITTY;
+  }
+  return 0;
+}
+
 // Qui si convien lasciare ogne sospetto; ogne viltà convien che qui sia morta.
 static int
-apply_term_heuristics(tinfo* ti, const char* termname, int fd){
+apply_term_heuristics(tinfo* ti, const char* termname, int fd,
+                      queried_terminals_e qterm){
   if(!termname){
     // setupterm interprets a missing/empty TERM variable as the special value “unknown”.
     termname = "unknown";
   }
+  if(qterm == TERMINAL_UNKNOWN){
+    match_termname(termname, &qterm);
+  }
+  // st had neithersextants nor quadrants last i checked (0.8.4)
   ti->braille = true; // most everyone has working braille, even from fonts
-  if(strstr(termname, "kitty")){ // kitty (https://sw.kovidgoyal.net/kitty/)
+  if(qterm == TERMINAL_KITTY){ // kitty (https://sw.kovidgoyal.net/kitty/)
     termname = "Kitty";
     // see https://sw.kovidgoyal.net/kitty/protocol-extensions.html
     // FIXME detect the actual default background color; this assumes it to
@@ -92,45 +108,33 @@ apply_term_heuristics(tinfo* ti, const char* termname, int fd){
     ti->quadrants = true;
     ti->RGBflag = true;
     setup_kitty_bitmaps(ti, fd);
-  }else if(strstr(termname, "alacritty")){
+  }else if(qterm == TERMINAL_ALACRITTY){
     termname = "Alacritty";
     ti->quadrants = true;
     // ti->sextants = true; // alacritty https://github.com/alacritty/alacritty/issues/4409 */
     ti->RGBflag = true;
-  }else if(strstr(termname, "vte") || strstr(termname, "gnome") || strstr(termname, "xfce")){
+  }else if(qterm == TERMINAL_VTE){
     termname = "VTE";
-    ti->sextants = true; // VTE has long enjoyed good sextant support
     ti->quadrants = true;
-  }else if(strncmp(termname, "foot", 4) == 0){
+    ti->sextants = true; // VTE has long enjoyed good sextant support
+  }else if(qterm == TERMINAL_FOOT){
     termname = "foot";
     ti->sextants = true;
     ti->quadrants = true;
     ti->RGBflag = true;
-  }else if(strncmp(termname, "st", 2) == 0){
-    termname = "simple terminal";
-    // st had neithersextants nor quadrants last i checked (0.8.4)
-  }else if(strstr(termname, "mlterm")){
+  }else if(qterm == TERMINAL_MLTERM){
     termname = "MLterm";
     ti->quadrants = true; // good quadrants, no sextants as of 3.9.0
     ti->sprixel_cursor_hack = true;
-  }else if(strstr(termname, "xterm")){
-    // xterm has nothing beyond halfblocks. this is going to catch all kinds
-    // of people using xterm when they shouldn't be, or even real database
-    // entries like "xterm-kitty" (if we don't catch them above), giving a
-    // pretty minimal (but safe) experience. set your TERM correctly!
-    // wezterm wants a TERM of xterm-256color, and identifies itself based
-    // off TERM_PROGRAM and TERM_PROGRAM_VERSION.
-    const char* term_program = getenv("TERM_PROGRAM");
-    if(term_program && strcmp(term_program, "WezTerm") == 0){
-      termname = "WezTerm";
-      ti->quadrants = true;
-      const char* termver = getenv("TERM_PROGRAM_VERSION");
-      if(termver && strcmp(termver, "20210610") >= 0){
-        ti->sextants = true; // good sextants as of 2021-06-10
-      }
-    }else{
-      termname = "XTerm";
+  }else if(qterm == TERMINAL_WEZTERM){
+    termname = "WezTerm";
+    ti->quadrants = true;
+    const char* termver = getenv("TERM_PROGRAM_VERSION");
+    if(termver && strcmp(termver, "20210610") >= 0){
+      ti->sextants = true; // good sextants as of 2021-06-10
     }
+  }else if(qterm == TERMINAL_XTERM){
+    termname = "XTerm";
   }else if(strcmp(termname, "linux") == 0){
     termname = "Linux console";
     ti->braille = false; // no braille, no sextants in linux console
@@ -399,7 +403,8 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname, unsigned utf8,
       goto err;
     }
   }
-  if(ncinputlayer_init(ti, stdin)){
+  queried_terminals_e detected;
+  if(ncinputlayer_init(ti, stdin, &detected)){
     goto err;
   }
   // our current sixel quantization algorithm requires at least 64 color
@@ -415,7 +420,8 @@ int interrogate_terminfo(tinfo* ti, int fd, const char* termname, unsigned utf8,
       }
     }
   }
-  if(apply_term_heuristics(ti, termname, fd)){
+//fprintf(stderr, "DETECTED TERM: %d\n", detected);
+  if(apply_term_heuristics(ti, termname, fd, detected)){
     ncinputlayer_stop(&ti->input);
     goto err;
   }

src/lib/termdesc.h

@@ -176,6 +176,7 @@ typedef enum {
   TERMINAL_FOOT,          // TDA: "\EP!|464f4f54\E\\"
   TERMINAL_MLTERM,        // XTGETTCAP['TN'] == 'mlterm'
   TERMINAL_WEZTERM,
+  TERMINAL_ALACRITTY,     // can't be detected; match TERM
 } queried_terminals_e;
 
 #ifdef __cplusplus