Fix case where "PM" to_timestamp() mask was eating too many characters.

Report from Josh Tolley.

src/backend/utils/adt/formatting.c

@@ -1,7 +1,7 @@
 /* -----------------------------------------------------------------------
  * formatting.c
  *
- * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.110 2006/04/19 18:49:09 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.111 2006/09/03 01:22:56 momjian Exp $
  *
  *
  *	 Portions Copyright (c) 1999-2006, PostgreSQL Global Development Group
@@ -1762,7 +1762,7 @@ dch_time(int arg, char *inout, int suf, bool is_to_char, bool is_interval,
 					tmfc->am = TRUE;
 				else
 					AMPM_ERROR;
-				return strlen(p_inout);
+				return strlen(P_M_STR);
 			}
 			break;
 		case DCH_AM:
@@ -1781,7 +1781,7 @@ dch_time(int arg, char *inout, int suf, bool is_to_char, bool is_interval,
 					tmfc->am = TRUE;
 				else
 					AMPM_ERROR;
-				return strlen(p_inout);
+				return strlen(PM_STR);
 			}
 			break;
 		case DCH_a_m:
@@ -1800,7 +1800,7 @@ dch_time(int arg, char *inout, int suf, bool is_to_char, bool is_interval,
 					tmfc->am = TRUE;
 				else
 					AMPM_ERROR;
-				return strlen(p_inout);
+				return strlen(p_m_STR);
 			}
 			break;
 		case DCH_am:
@@ -1819,7 +1819,7 @@ dch_time(int arg, char *inout, int suf, bool is_to_char, bool is_interval,
 					tmfc->am = TRUE;
 				else
 					AMPM_ERROR;
-				return strlen(p_inout);
+				return strlen(pm_STR);
 			}
 			break;
 		case DCH_HH: