From 286c6b868dd46b2c90bd828f2c11413752c99456 Mon Sep 17 00:00:00 2001
From: simon <simon@cda61777-01e9-0310-a592-d414129be87e>
Date: Tue, 23 Oct 2001 19:51:23 +0000
Subject: [PATCH] Better robustness in visual bell timeouts: handling
 GetTickCount wraparound, not referencing vbell_timeout if in_vbell==FALSE,
 that sort of thing. I doubt it'll fix the reported problems with screen
 vbells, since none of the failure modes I've just prevented looked all that
 probable to me, but it's nice to have extra robustness anyway.

git-svn-id: svn://svn.tartarus.org/sgt/putty@1314 cda61777-01e9-0310-a592-d414129be87e
---
 putty.h    |  2 +-
 terminal.c | 36 +++++++++++++++++++++---------------
 2 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/putty.h b/putty.h
index cdab4aa8..026fa44c 100644
--- a/putty.h
+++ b/putty.h
@@ -96,7 +96,7 @@ GLOBAL int rows, cols, savelines;
 GLOBAL int has_focus;
 
 GLOBAL int in_vbell;
-GLOBAL long vbell_timeout;
+GLOBAL unsigned long vbell_startpoint;
 
 GLOBAL int app_cursor_keys, app_keypad_keys, vt52_mode;
 GLOBAL int repeat_off, cr_lf_return;
diff --git a/terminal.c b/terminal.c
index a65d7157..5cd4c17f 100644
--- a/terminal.c
+++ b/terminal.c
@@ -63,7 +63,7 @@ static unsigned long curstype;	       /* type of cursor on real screen */
 
 struct beeptime {
     struct beeptime *next;
-    long ticks;
+    unsigned long ticks;
 };
 static struct beeptime *beephead, *beeptail;
 int nbeeps;
@@ -97,7 +97,7 @@ static int cset;		       /* 0 or 1: which char set */
 static int save_cset, save_csattr;     /* saved with cursor position */
 static int save_utf;     	       /* saved with cursor position */
 static int rvideo;		       /* global reverse video flag */
-static int rvbell_timeout;	       /* for ESC[?5hESC[?5l vbell */
+static unsigned long rvbell_startpoint;/* for ESC[?5hESC[?5l vbell */
 static int cursor_on;		       /* cursor enabled flag */
 static int reset_132;		       /* Flag ESC c resets to 80 cols */
 static int use_bce;		       /* Use Background coloured erase */
@@ -848,7 +848,7 @@ static void insch(int n)
  */
 static void toggle_mode(int mode, int query, int state)
 {
-    long ticks;
+    unsigned long ticks;
 
     if (query)
 	switch (mode) {
@@ -877,14 +877,20 @@ static void toggle_mode(int mode, int query, int state)
 	     * always be an actually _visible_ visual bell.
 	     */
 	    ticks = GetTickCount();
-	    if (rvideo && !state &&    /* we're turning it off */
-		ticks < rvbell_timeout) {	/* and it's not long since it was turned on */
+	    /* turn off a previous vbell to avoid inconsistencies */
+	    if (ticks - vbell_startpoint >= VBELL_TIMEOUT)
+		in_vbell = FALSE;
+	    if (rvideo && !state &&    /* we're turning it off... */
+		(ticks - rvbell_startpoint) < VBELL_TIMEOUT) {	/* ...soon */
+		/* If there's no vbell timeout already, or this one lasts
+		 * longer, replace vbell_timeout with ours. */
+		if (!in_vbell ||
+		    (rvbell_startpoint - vbell_startpoint < VBELL_TIMEOUT))
+		    vbell_startpoint = rvbell_startpoint;
 		in_vbell = TRUE;       /* we may clear rvideo but we set in_vbell */
-		if (vbell_timeout < rvbell_timeout)	/* don't move vbell end forward */
-		    vbell_timeout = rvbell_timeout;	/* vbell end is at least then */
 	    } else if (!rvideo && state) {
 		/* This is an ON, so we notice the time and save it. */
-		rvbell_timeout = ticks + VBELL_TIMEOUT;
+		rvbell_startpoint = ticks;
 	    }
 	    rvideo = state;
 	    seen_disp_event = TRUE;
@@ -1194,7 +1200,7 @@ void term_out(void)
 	      case '\007':
 		{
 		    struct beeptime *newbeep;
-		    long ticks;
+		    unsigned long ticks;
 
 		    ticks = GetTickCount();
 
@@ -1225,7 +1231,7 @@ void term_out(void)
 		    }
 
 		    if (cfg.bellovl && beep_overloaded &&
-			ticks - lastbeep >= cfg.bellovl_s) {
+			ticks - lastbeep >= (unsigned)cfg.bellovl_s) {
 			/*
 			 * If we're currently overloaded and the
 			 * last beep was more than s seconds ago,
@@ -1250,7 +1256,7 @@ void term_out(void)
 			beep(cfg.beep);
 			if (cfg.beep == BELL_VISUAL) {
 			    in_vbell = TRUE;
-			    vbell_timeout = ticks + VBELL_TIMEOUT;
+			    vbell_startpoint = ticks;
 			    term_update();
 			}
 		    }
@@ -2528,16 +2534,16 @@ static void do_paint(Context ctx, int may_optimise)
     pos scrpos;
     char ch[1024];
     long cursor_background = ERASE_CHAR;
-    long ticks;
+    unsigned long ticks;
 
     /*
      * Check the visual bell state.
      */
     if (in_vbell) {
 	ticks = GetTickCount();
-	if (ticks - vbell_timeout >= 0)
-	    in_vbell = FALSE;
-    }
+	if (ticks - vbell_startpoint >= VBELL_TIMEOUT)
+	    in_vbell = FALSE; 
+   }
 
     rv = (!rvideo ^ !in_vbell ? ATTR_REVERSE : 0);
 
-- 
2.11.0