make in_history() sensible of 'firstc' (vim)

ex_getln.c.diff

--- ex_getln.c.orig	2011-07-20 22:35:22.540320700 +0900
+++ ex_getln.c	2011-07-20 22:48:04.029204400 +0900
@@ -67,7 +67,7 @@
 
 static int	hist_char2type __ARGS((int c));
 
-static int	in_history __ARGS((int, char_u *, int));
+static int	in_history __ARGS((int, char_u *, int, int));
 # ifdef FEAT_EVAL
 static int	calc_hist_idx __ARGS((int histype, int num));
 # endif
@@ -5306,10 +5306,11 @@
  * If 'move_to_front' is TRUE, matching entry is moved to end of history.
  */
     static int
-in_history(type, str, move_to_front)
+in_history(type, str, move_to_front, sep)
     int	    type;
     char_u  *str;
     int	    move_to_front;	/* Move the entry to the front if it exists */
+    int	    sep;
 {
     int	    i;
     int	    last_i = -1;
@@ -5323,6 +5324,13 @@
 	    return FALSE;
 	if (STRCMP(str, history[type][i].hisstr) == 0)
 	{
+	    char_u *p = history[type][i].hisstr;
+
+	    /* For search history, equation check includes first characters
+	     * equation. */
+	    if (type == HIST_SEARCH && sep != p[STRLEN(p) + 1])
+		break;
+
 	    if (!move_to_front)
 		return TRUE;
 	    last_i = i;
@@ -5415,7 +5423,7 @@
 	}
 	last_maptick = -1;
     }
-    if (!in_history(histype, new_entry, TRUE))
+    if (!in_history(histype, new_entry, TRUE, sep))
     {
 	if (++hisidx[histype] == hislen)
 	    hisidx[histype] = 0;
@@ -5994,7 +6002,7 @@
 	if (val != NULL && *val != NUL)
 	{
 	    if (!in_history(type, val + (type == HIST_SEARCH),
-							viminfo_add_at_front))
+			viminfo_add_at_front, *val))
 	    {
 		/* Need to re-allocate to append the separator byte. */
 		len = STRLEN(val);