Fix timezone handling in ippDateToTime, add unit tests.

Author: michaelrsweet

CHANGES.md

@@ -1,6 +1,12 @@
 Changes in libcups
 ==================
 
+libcups v3.0.0 (YYYY-MM-DD)
+---------------------------
+
+- Fixed return values of `ippDateToTime` when the timezone isn't GMT.
+
+
 libcups v3.0rc4 (2025-03-18)
 ----------------------------
 

config.h.in

@@ -1,7 +1,7 @@
 //
 // Configuration file for libcups.
 //
-// Copyright © 2020-2024 by OpenPrinting
+// Copyright © 2020-2025 by OpenPrinting
 // Copyright © 2007-2019 by Apple Inc.
 // Copyright © 1997-2007 by Easy Software Products.
 //
@@ -144,6 +144,13 @@
 #undef HAVE_TM_GMTOFF
 
 
+//
+// Do we have the timegm function?
+//
+
+#undef HAVE_TIMEGM
+
+
 //
 // Do we have hstrerror()?
 //

configure

@@ -4712,6 +4712,19 @@ printf "%s\n" "no" >&6; }
 fi
 rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
 
+
+ac_fn_c_check_func "$LINENO" "timegm" "ac_cv_func_timegm"
+if test "x$ac_cv_func_timegm" = xyes
+then :
+
+
+printf "%s\n" "#define HAVE_TIMEGM 1" >>confdefs.h
+
+
+fi
+
+
+
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for long long int" >&5
 printf %s "checking for long long int... " >&6; }
 if test ${ac_cv_c_long_long+y}

configure.ac

@@ -246,6 +246,13 @@ AC_COMPILE_IFELSE([
     AC_MSG_RESULT([no])
 ])
 
+
+dnl See if we have the timegm function...
+AC_CHECK_FUNC([timegm], [
+    AC_DEFINE([HAVE_TIMEGM], [1], [Do we have the timegm function?])
+])
+
+
 dnl Check for "long long" support...
 AC_CACHE_CHECK([for long long int], [ac_cv_c_long_long], [
     AS_IF([test "$GCC" = yes], [

cups/ipp.c

@@ -1605,7 +1605,7 @@ ippDateToTime(const ipp_uchar_t *date)	// I - RFC 2579 date info
   //    6        Seconds (0 to 60, 60 = "leap second")
   //    7        Deciseconds (0 to 9)
   //    8        +/- UTC
-  //    9        UTC hours (0 to 11)
+  //    9        UTC hours (0 to 14)
   //    10       UTC minutes (0 to 59)
   unixdate.tm_year = ((date[0] << 8) | date[1]) - 1900;
   unixdate.tm_mon  = date[2] - 1;
@@ -1614,9 +1614,24 @@ ippDateToTime(const ipp_uchar_t *date)	// I - RFC 2579 date info
   unixdate.tm_min  = date[5];
   unixdate.tm_sec  = date[6];
 
+#if _WIN32
+  if ((t = _mkgmtime(&unixdate)) < 0)
+    return (0);
+#elif defined(HAVE_TIMEGM)
+  if ((t = timegm(&unixdate)) < 0)
+    return (0);
+#else
   if ((t = mktime(&unixdate)) < 0)
     return (0);
 
+#  if defined(HAVE_TM_GMTOFF)
+  localtime_r(&t, &unixdate);
+  t -= unixdate.tm_gmtoff;
+#  else
+  t -= timezone;
+#  endif // HAVE_TM_GMTOFF
+#endif // _WIN32
+
   if (date[8] == '-')
     t += date[9] * 3600 + date[10] * 60;
   else

cups/testipp.c

@@ -1,7 +1,7 @@
 //
 // IPP unit test program for libcups.
 //
-// Copyright © 2021-2024 by OpenPrinting.
+// Copyright © 2021-2025 by OpenPrinting.
 // Copyright © 2007-2019 by Apple Inc.
 // Copyright © 1997-2005 by Easy Software Products.
 //
@@ -314,6 +314,8 @@ main(int  argc,				// I - Number of command-line arguments
   cups_file_t	*fp;			// File pointer
   size_t	i;			// Looping var
   int		status = 0;		// Status of tests (0 = success, 1 = fail)
+  time_t	tv;			// Time value
+  const ipp_uchar_t *dv;		// Date value
 #ifdef DEBUG
   const char	*name;			// Option name
 #endif // DEBUG
@@ -734,6 +736,42 @@ main(int  argc,				// I - Number of command-line arguments
     // Test ippFile API...
     status |= test_file(/*color*/NULL);
     status |= test_file("blue");
+
+    // Test ippDateToTime and ippTimeToDate
+    testBegin("ippDateToTime(1970/01/02T00:00:00Z)");
+    buffer[0]  = 1970 >> 8;		// Year MSB
+    buffer[1]  = 1970 & 255;		// Year LSB
+    buffer[2]  = 1;			// Month
+    buffer[3]  = 2;			// Day
+    buffer[4]  = 0;			// Hour
+    buffer[5]  = 0;			// Minute
+    buffer[6]  = 0;			// Second
+    buffer[7]  = 0;			// Deci-second
+    buffer[8]  = '+';			// Timezone +/-
+    buffer[9]  = 0;			// Timezone hours
+    buffer[10] = 0;			// Timezone minutes
+
+    if ((tv = ippDateToTime(buffer)) == 86400)
+    {
+      testEnd(true);
+    }
+    else
+    {
+      testEndMessage(false, "got %ld, expected 86400", (long)tv);
+      status = 1;
+    }
+
+    testBegin("ippTimeToDate(86400)");
+
+    if ((dv = ippTimeToDate(86400)) != NULL && !memcmp(dv, buffer, 11))
+    {
+      testEnd(true);
+    }
+    else
+    {
+      testEndMessage(false, "got %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X, expected %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", dv[0], dv[1], dv[2], dv[3], dv[4], dv[5], dv[6], dv[7], dv[8], dv[9], dv[10], buffer[0], buffer[1], buffer[2], buffer[3], buffer[4], buffer[5], buffer[6], buffer[7], buffer[8], buffer[9], buffer[10]);
+      status = 1;
+    }
   }
   else
   {