[PATCH 2/5] keyboard input: add commented-out debugging logging mechanism.

[Denys Vlasenko <vda linux googlemail com>]

Figuring out what exactly happens in get_key_code() when user
uses various function keys is not trivial.
While working on some fixes, I added a debugging code
which records a log in /tmp/mc_key.log; I would like
to save future developers from doing this again.

This patch adds my debugging code, disabled via "#if 0".

Signed-off-by: Denys Vlasenko <vda linux googlemail com>
---
 lib/tty/key.c |   55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 55 insertions(+), 0 deletions(-)

diff --git a/lib/tty/key.c b/lib/tty/key.c
index d2142fa..33732db 100644
--- a/lib/tty/key.c
+++ b/lib/tty/key.c
@@ -1811,6 +1811,34 @@ is_idle (void)
 }
 
 /* --------------------------------------------------------------------------------------------- */
+#if 0
+# define key_debug 1
+static void keylog (const char *fmt, ...)
+{
+    static int logfd = -1;
+
+    if (logfd < 0) {
+        logfd = open ("/tmp/mc_key.log", O_CREAT | O_WRONLY | O_APPEND, 0666);
+        if (logfd < 0)
+            return;
+    }
+
+    va_list ap;
+    va_start (ap, fmt);
+    char *p = NULL;
+    vasprintf (&p, fmt, ap);
+    va_end (ap);
+
+    if (p)
+    {
+        write (logfd, p, strlen(p));
+        free (p);
+    }
+}
+#else
+# define key_debug 0
+# define keylog(...) ((void)0)
+#endif
 
 int
 get_key_code (int no_delay)
@@ -1820,6 +1848,8 @@ get_key_code (int no_delay)
     static struct timeval esctime = { -1, -1 };
     static int lastnodelay = -1;
 
+    keylog ("entered %s(no_delay:%d)\n", __func__, no_delay);
+
     if (no_delay != lastnodelay)
     {
         this = NULL;
@@ -1832,15 +1862,18 @@ get_key_code (int no_delay)
         int m;
 
         m = parse_extended_mouse_coordinates ();
+        keylog (" pending_keys!=NULL. m=%d\n", m);
         if (m == 1)
         {
             pending_keys = seq_append = NULL;
             this = NULL;
+            keylog ("return MCKEY_EXTENDED_MOUSE\n");
             return MCKEY_EXTENDED_MOUSE;
         }
         if (m == -1)
         {
             int d = *pending_keys++;
+            keylog (" d=*pending_keys++=%d\n", d);
           check_pend:
             if (*pending_keys == 0)
             {
@@ -1850,11 +1883,16 @@ get_key_code (int no_delay)
             else if (d == ESC_CHAR)
             {
                 d = ALT (*pending_keys++);
+                keylog (" d=ALT(*pending_keys++)=ALT(%d)=%d\n", pending_keys[-1], d);
                 goto check_pend;
             }
             if ((d > 127 && d < 256) && use_8th_bit_as_meta)
+            {
                 d = ALT (d & 0x7f);
+                keylog (" d=ALT(d & 0x7f)=ALT(%d)=%d\n", d & 0x7f, d);
+            }
             this = NULL;
+            keylog ("return correct_key_code(%d)\n", d);
             return correct_key_code (d);
         }
         /* else if (m == 0), just let it continue */
@@ -1865,6 +1903,7 @@ get_key_code (int no_delay)
         tty_nodelay (TRUE);
 
     c = tty_lowlevel_getch ();
+    keylog (" c=tty_lowlevel_getch()=%d\n", c);
 #if (defined(USE_NCURSES) || defined(USE_NCURSESW)) && defined(KEY_RESIZE)
     if (c == KEY_RESIZE)
         goto nodelay_try_again;
@@ -1941,15 +1980,18 @@ get_key_code (int no_delay)
                 pending_keys = seq_append = NULL;
                 code = this->code;
                 this = NULL;
+                keylog ("2 return correct_key_code(%d)\n", code);
                 return correct_key_code (code);
             }
             /* No match yet, but it may be a prefix for a valid seq */
 
             if (!push_char (c))
             {
+                keylog (" push_char(%d) failure (no more space)\n", c);
                 pending_keys = seq_buffer;
                 goto pend_send;
             }
+            keylog (" push_char(%d) ok\n", c);
             parent = this;
             this = this->child;
             if (parent->action == MCKEY_ESCAPE && old_esc_mode)
@@ -1967,10 +2009,12 @@ get_key_code (int no_delay)
                 }
                 esctime.tv_sec = -1;
                 c = xgetch_second ();
+                keylog (" c=xgetch_second()=%d\n", c);
                 if (c == -1)
                 {
                     pending_keys = seq_append = NULL;
                     this = NULL;
+                    keylog ("return ESC_CHAR\n");
                     return ESC_CHAR;
                 }
                 continue;
@@ -1978,6 +2022,7 @@ get_key_code (int no_delay)
             if (no_delay)
                 goto nodelay_try_again;
             c = tty_lowlevel_getch ();
+            keylog (" 2 c=tty_lowlevel_getch()=%d\n", c);
             continue;
         }
 
@@ -2000,17 +2045,27 @@ get_key_code (int no_delay)
 
             pending_keys = seq_append = NULL;
             this = NULL;
+            keylog ("3 return correct_key_code(%d)\n", c);
             return correct_key_code (c);
         }
 
         /* Unknown sequence. Maybe a prefix of a longer one. Save it. */
+        keylog (" push_char(%d)\n", c);
         push_char (c);
+        if (key_debug)
+        {
+            int i = 0;
+            do
+                keylog ("  seq_buffer[%d]:%d\n", i, seq_buffer[i]);
+            while (seq_buffer[i++]);
+        }
         pending_keys = seq_buffer;
         goto pend_send;
 
     } /* while (this != NULL) */
 
     this = NULL;
+    keylog ("4 return correct_key_code(%d)\n", c);
     return correct_key_code (c);
 }
 
-- 
1.7.7.6