Wrote some code to try and un-mangle broken date formats and then parse

2000-06-30  Jeffrey Stedfast  <fejj@helixcode.com>

	* camel-mime-utils.c (header_decode_date): Wrote some code to try
	and un-mangle broken date formats and then parse that new string
	instead.

svn path=/trunk/; revision=3836

1 files changed, 314 insertions, 12 deletions

diff --git a/camel/camel-mime-utils.c b/camel/camel-mime-utils.c
index 85016ed245..fbae08a946 100644
--- a/camel/camel-mime-utils.c
+++ b/camel/camel-mime-utils.c
@@ -138,6 +138,14 @@ enum {
 #define CHARS_CSPECIAL "()\\\r"	/* not in comments */
 #define CHARS_DSPECIAL "[]\\\r \t"	/* not in domains */
 
+/* prototypes for functions dealing with broken date formats */
+static GList *datetok (const gchar *date)
+static gint get_days_in_month (gint mon, gint year);
+static gint get_weekday (gchar *str);
+static gint get_month (gchar *str);
+static gchar *parse_date (const gchar *datestr);
+
+
 static void
 header_init_bits(unsigned char bit, unsigned char bitcopy, int remove, unsigned char *vals, int len)
 {
@@ -1342,7 +1350,8 @@ header_decode_mailbox(const char **in)
 	/* for each address */
 	pre = header_decode_word(&inptr);
 	header_decode_lwsp(&inptr);
-	if (!(*inptr == '.' || *inptr == '@' || *inptr==',' || *inptr=='\0')) {	/* ',' and '\0' required incase it is a simple address, no @ domain part (buggy writer) */
+	if (!(*inptr == '.' || *inptr == '@' || *inptr==',' || *inptr=='\0')) {
+		/* ',' and '\0' required incase it is a simple address, no @ domain part (buggy writer) */
 		name = g_string_new("");
 		while (pre) {
 			char *text;
@@ -1930,6 +1939,287 @@ header_format_date(time_t time, int offset)
 			       offset);
 }
 
+/*********************************************************************************
+ *   The following functions are here in the case of badly broken date formats   *
+ *                                                                               *
+ *   -- fejj@helixcode.com                                                       *
+ *********************************************************************************/
+
+typedef struct {
+	gchar dow[6];   /* day of week (should only need 4 chars) */
+	gint day;
+	gint mon;       /* 1->12 or 0 if invalid */
+	gint year;
+	gint hour;
+	gint min;
+	gint sec;
+	gchar zone[6];  /* time zone */
+} date_t;
+
+static
+GList *datetok (const gchar *date)
+{
+	GList *tokens = NULL;
+	gchar *token, *start, *end;
+
+	start = (gchar *) date;
+	while (*start) {
+		/* find the end of this token */
+		for (end = start; *end && *end != ' '; end++);
+
+		token = g_strndup (start, (end - start));
+
+		if (token && *token)
+			tokens = g_list_append (tokens, token);
+		else
+			g_free (token);
+
+		if (*end)
+			start = end + 1;
+		else
+			break;
+	}
+
+	return tokens;
+}
+
+static gint
+get_days_in_month (gint mon, gint year)
+{
+	switch (mon) {
+	case 1: case 3: case 5: case 7: case 8: case 10: case 12:
+		return 31;
+	case 4: case 6: case 9: case 11:
+		return 30;
+	case 2:
+		if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
+			return 29;
+		return 28;
+	default:
+		return 30;
+	}
+}
+
+static gint
+get_weekday (gchar *str)
+{
+	g_return_val_if_fail ((str != NULL), 0);
+
+	if (strncmp (str, "Mon", 3) == 0) {
+		return 1;
+	} else if (strncmp (str, "Tue", 3) == 0) {
+		return 2;
+	} else if (strncmp (str, "Wed", 3) == 0) {
+		return 3;
+	} else if (strncmp (str, "Thu", 3) == 0) {
+		return 4;
+	} else if (strncmp (str, "Fri", 3) == 0) {
+		return 5;
+	} else if (strncmp (str, "Sat", 3) == 0) {
+		return 6;
+	} else if (strncmp (str, "Sun", 3) == 0) {
+		return 7;
+	}
+
+	return 0;  /* unknown week day */
+}
+
+static gint
+get_month (gchar *str)
+{
+	g_return_val_if_fail (str != NULL, 0);
+    
+	if (strncmp (str, "Jan", 3) == 0) {
+		return 1;
+	} else if (strncmp (str, "Feb", 3) == 0) {
+		return 2;
+	} else if (strncmp (str, "Mar", 3) == 0) {
+		return 3;
+	} else if (strncmp (str, "Apr", 3) == 0) {
+		return 4;
+	} else if (strncmp (str, "May", 3) == 0) {
+		return 5;
+	} else if (strncmp (str, "Jun", 3) == 0) {
+		return 6;
+	} else if (strncmp (str, "Jul", 3) == 0) {
+		return 7;
+	} else if (strncmp (str, "Aug", 3) == 0) {
+		return 8;
+	} else if (strncmp (str, "Sep", 3) == 0) {
+		return 9;
+	} else if (strncmp (str, "Oct", 3) == 0) {
+		return 10;
+	} else if (strncmp (str, "Nov", 3) == 0) {
+		return 11;
+	} else if (strncmp (str, "Dec", 3) == 0) {
+		return 12;
+	}
+    
+	return 0;  /* unknown month */
+}
+
+static gchar *
+parse_date (const gchar *datestr)
+{
+	GList *tokens;
+	date_t date;
+	gchar *token, *ptr, *newdatestr;
+	guint len, i, retval;
+	gdouble tz = 0.0;
+	
+	memset ((void*)&date, 0, sizeof (date_t));
+	g_return_val_if_fail (datestr != NULL, NULL);
+	
+	tokens = datetok (datestr);
+	len = g_list_length (tokens);
+	for (i = 0; i < len; i++) {
+		token = g_list_nth_data (tokens, i);
+		
+		if ((retval = get_weekday (token))) {
+			strncpy (date.dow, datestr, 4);
+		} else if ((retval = get_month (token))) {
+			date.mon = retval;
+		} else if (strlen (token) <= 2) {
+			/* this could be a 1 or 2 digit day of the month */
+			for (retval = 1, ptr = token; *ptr; ptr++)
+				if (*ptr < '0' || *ptr > '9')
+					retval = 0;
+			
+			if (retval && atoi (token) <= 31 && !date.day)  /* probably should find a better way */
+				date.day = atoi (token);
+			else                                            /* fubar'd client using a 2-digit year */
+				date.year = atoi (token) < 69 ? 2000 + atoi (token) : 1900 + atoi (token);
+		} else if (strlen (token) == 4) {
+			/* this could be the year... */
+			for (retval = 1, ptr = token; *ptr; ptr++)
+				if (*ptr < '0' || *ptr > '9')
+					retval = 0;
+			
+			if (retval)
+				date.year = atoi (token);
+		} else if (strchr (token, ':')) {
+			/* this must be the time: hh:mm:ss */
+			sscanf (token, "%d:%d:%d", &date.hour, &date.min, &date.sec);
+		} else if (*token == '-' || *token == '+') {
+			tz = atoi (token) / 100.0;
+		}
+	}
+	
+	g_list_free (tokens);
+	
+	/* adjust times based on time zones */
+	
+	if (tz != 0) {
+		/* check for time-zone shift */
+		if (tz > 0) {
+			/* correct for positive hours off of UCT */
+			date.hour -= (tz / 100);
+			tz = (gint)tz % 100;
+			
+			if (tz > 0) /* correct for positive minutes off of UCT */
+				date.min -= (gint)(((gdouble) tz / 100.0) * 60.0);
+		} else {
+			if (tz < 0) {
+				/* correct for negative hours off of UCT */
+				tz = -tz;
+				date.hour += (tz / 100);
+				tz = -((gint)tz % 100);
+				
+				if (tz < 0)
+					date.min -= (gint)(((gdouble) tz / 100.0) * 60.0);
+			}
+		}
+		
+		/* adjust seconds to proper range */
+		if (date.sec > 59) {
+			date.min += (date.sec / 60);
+			date.sec = (date.sec % 60);
+		}
+		
+		/* adjust minutes to proper range */
+		if (date.min > 59) {
+			date.hour += (date.min / 60);
+			date.min = (date.min % 60);
+		} else {
+			if (date.min < 0) {
+				date.min = -date.min;
+				date.hour -= (date.min / 60) - 1;
+				date.min = 60 - (date.min % 60);
+			}
+		}
+		
+		/* adjust hours to the proper randge */
+		if (date.hour > 23) {
+			date.day += (date.hour / 24);
+			date.hour -= (date.hour % 24);
+		} else {
+			if (date.hour < 0) {
+				date.hour = -date.hour;
+				date.day -= (date.hour / 24) - 1;
+				date.hour = 24 - (date.hour % 60);
+			}
+		}
+		
+		/* adjust days to the proper range */
+		while (date.day > get_days_in_month (date.mon, date.year)) {
+			date.day -= get_days_in_month (date.mon, date.year);
+			date.mon++;
+			if (date.mon > 12) {
+				date.year += (date.mon / 12);
+				date.mon = (date.mon % 12);
+				if (date.mon == 0) {
+					/* month sanity check */
+					date.mon = 12;
+					date.year -= 1;
+				}
+			}
+		}
+		
+		while (date.day < 1) {
+			date.day += get_days_in_month (date.mon, date.year);
+			date.mon--;
+			if (date.mon < 1) {
+				date.mon = -date.mon;
+				date.year -= (date.mon / 12) - 1;
+				date.mon = 12 - (date.mon % 12);
+			}
+		}
+		
+		/* adjust months to the proper range */
+		if (date.mon > 12) {
+			date.year += (date.mon / 12);
+			date.mon = (date.mon % 12);
+			if (date.mon == 0) {
+				/* month sanity check */
+				date.mon = 12;
+				date.year -= 1;
+			}
+		} else {
+			if (date.mon < 1) {
+				date.mon = -date.mon;
+				date.year -= (date.mon / 12) - 1;
+				date.mon = 12 - (date.mon % 12);
+			}
+		}
+	}
+
+	/* now lets print this date into a string with the correct format */
+	newdatestr = g_strdup_printf ("%s, %d %s %d %s%d:%s%d:%s%d -0000",
+				      date.dow, date.day, tz_months[date.mon-1],
+				      date.year,
+				      date.hour > 10 ? "" : "0", date.hour,
+				      date.min > 10 ? "" : "0", date.min,
+				      date.sec > 10 ? "" : "0", date.sec);
+	
+	return newdatestr;
+}
+
+/*********************************************************************************
+ *   This ends the code for the broken date parser...                            *
+ *                                                                               *
+ *   -- fejj@helixcode.com                                                       *
+ *********************************************************************************/
+
 /* convert a date to time_t representation */
 /* this is an awful mess oh well */
 time_t
@@ -1948,22 +2238,34 @@ header_decode_date(const char *in, int *saveoffset)
 		return 0;
 	}
 
-	d(printf("\ndecoding date '%s'\n", inptr));
+	d(printf ("\ndecoding date '%s'\n", inptr));
 
-	memset(&tm, 0, sizeof(tm));
+	memset (&tm, 0, sizeof(tm));
 
-	header_decode_lwsp(&inptr);
-	if (!isdigit(*inptr)) {
-		char *day = decode_token(&inptr);
+	header_decode_lwsp (&inptr);
+	if (!isdigit (*inptr)) {
+		char *day = decode_token (&inptr);
 		/* we dont really care about the day, its only for display */
 		if (day) {
-			d(printf("got day: %s\n", day));
-			g_free(day);
-			header_decode_lwsp(&inptr);
-			if (*inptr == ',')
+			d(printf ("got day: %s\n", day));
+			g_free (day);
+			header_decode_lwsp (&inptr);
+			if (*inptr == ',') {
 				inptr++;
-			else {
-				w(g_warning("day not followed by ',' its probably a broken TradeClient, so we'll ignore its date entirely"));
+			} else {
+				gchar *newdate;
+				
+				w(g_warning("day not followed by ',' its probably a broken mail client, so we'll ignore its date entirely"));
+				printf ("Giving it one last chance...\n");
+				newdate = parse_date (in);
+				if (FALSE && newdate) {
+					printf ("Got: %s\n", newdate);
+					if (saveoffset)
+						*saveoffset = 0;					
+					t =  header_decode_date (newdate, NULL);
+					g_free (newdate);
+				}
+				
 				if (saveoffset)
 					*saveoffset = 0;
 				return 0;