[gs-cvs] rev 8291 - trunk/gs/src

[ken at ghostscript.com]

Author: ken
Date: 2007-10-15 06:11:16 -0700 (Mon, 15 Oct 2007)
New Revision: 8291

Modified:
   trunk/gs/src/gdevpdf.c
Log:
pdfwrite: When writing the /CreationDate /ModDate keys in the Info dictionary,
properly write the system local time instead of UTC.

DETAILS:
Bug #688783 "commit 6892 mis-uses the TZ environmental"

A rather lengthy thread, but in essence quite simple. A change to calculate
the system local time as an offset from UTC, and store this information in 
the form described in the PDF Reference (Section 3.8.3 "Dates" on p133 of 
the 1.6 PDF Reference).

The patch uses code supplied by SaGS.

(gdevpdf.c) pdf_initialize_ids, use the C runtime 'time' and 'gmtime' to 
determine the difference between local system time and GMT. Use this to 
calculate the difference (positive, negative, or none) from GMT, and the
number of hours and minutes comprising the difference. Use 'localtime' to
find the local system date and time.

Take all of the information from above, and format the result according to
the specification in the PDF Reference:

(D:YYYYMMDDhhmmssZhh'mm')

Where YYYY=4 digit local time year
        MM=2 digit local time month
        DD=2 digit local time day
        hh=2 digit local time hours (24 hour)
        mm=2 digit local time minutes
        ss=2 digit local time seconds
         Z=offset of local time from UTC
           Z=no difference
           +=local time later than UTC
           -=local time earlier than UTC
       hh'=hours difference between local time and UTC
       mm'=minutes difference between local time and UTC

EXPECTED DIFFERENCES:
None

Modified: trunk/gs/src/gdevpdf.c
===================================================================
--- trunk/gs/src/gdevpdf.c	2007-10-15 06:43:04 UTC (rev 8290)
+++ trunk/gs/src/gdevpdf.c	2007-10-15 13:11:16 UTC (rev 8291)
@@ -273,16 +273,25 @@
      * PostScript file.  We think this is wrong, but we do the same.
      */
     {
-	struct tm tms;
+        struct tm tms;
 	time_t t;
-	char buf[1+2+4+2+2+2+2+2+2+1+1+7]; /* (D:yyyymmddhhmmssZhh'mm')\0 */
+        char buf[1+2+4+2+2+2+2+2+1+2+1+2+1+1+1]; /* (D:yyyymmddhhmmssZhh'mm')\0 */
+	int timeoffset;
+        char timesign;
 
 	time(&t);
 	tms = *gmtime(&t);
-	sprintf(buf,
-		"(D:%04d%02d%02d%02d%02d%02dZ)",
-		tms.tm_year + 1900, tms.tm_mon + 1, tms.tm_mday,
-		tms.tm_hour, tms.tm_min, tms.tm_sec);
+        tms.tm_isdst = -1;
+	timeoffset = (int)difftime(t, mktime(&tms)); /* tz+dst in seconds */
+        timesign = (timeoffset == 0 ? 'Z' : timeoffset < 0 ? '-' : '+');
+	timeoffset = any_abs(timeoffset) / 60;
+        tms = *localtime(&t);
+
+	sprintf(buf, "(D:%04d%02d%02d%02d%02d%02d%c%02d\'%02d\')",
+	    tms.tm_year + 1900, tms.tm_mon + 1, tms.tm_mday,
+	    tms.tm_hour, tms.tm_min, tms.tm_sec,
+	    timesign, timeoffset / 60, timeoffset % 60);
+
 	cos_dict_put_c_key_string(pdev->Info, "/CreationDate", (byte *)buf,
 				  strlen(buf));
 	cos_dict_put_c_key_string(pdev->Info, "/ModDate", (byte *)buf,