[avr-libc-commit] [2537] util/eu_dst.h: Fix reversed DST decision logic for March and October

[j]

Revision: 2537
          http://svn.sv.gnu.org/viewvc/?view=rev&root=avr-libc&revision=2537
Author:   joerg_wunsch
Date:     2017-03-31 15:46:35 -0400 (Fri, 31 Mar 2017)
Log Message:
-----------
util/eu_dst.h: Fix reversed DST decision logic for March and October

Modified Paths:
--------------
    trunk/avr-libc/ChangeLog
    trunk/avr-libc/NEWS
    trunk/avr-libc/include/util/eu_dst.h

Modified: trunk/avr-libc/ChangeLog
===================================================================
--- trunk/avr-libc/ChangeLog    2017-03-07 07:13:41 UTC (rev 2536)
+++ trunk/avr-libc/ChangeLog    2017-03-31 19:46:35 UTC (rev 2537)
@@ -1,3 +1,8 @@
+2017-03-31  Joerg Wunsch <address@hidden>
+
+       * include/util/eu_dst.h: Fix reversed DST decision logic for March
+       and October.
+
 2017-03-07  Pitchumani Sivanupandi <address@hidden>
 
        Fix for bug #50439: avr/iom32u4.h does not define PRTIM4

Modified: trunk/avr-libc/NEWS
===================================================================
--- trunk/avr-libc/NEWS 2017-03-07 07:13:41 UTC (rev 2536)
+++ trunk/avr-libc/NEWS 2017-03-31 19:46:35 UTC (rev 2537)
@@ -9,6 +9,7 @@
   [#49447] Example code for uart_putchar() has error in recursive call
   strings for storage in program memory
   [#50439] avr/iom32u4.h does not define PRTIM4
+  [no-id] util/eu_dst.h: fix reversed DST decision logic for March and October
 
 * New devices supported:
 

Modified: trunk/avr-libc/include/util/eu_dst.h
===================================================================
--- trunk/avr-libc/include/util/eu_dst.h        2017-03-07 07:13:41 UTC (rev 
2536)
+++ trunk/avr-libc/include/util/eu_dst.h        2017-03-31 19:46:35 UTC (rev 
2537)
@@ -88,24 +88,25 @@
                         n = 31 - d;
                         n /= 7; /* number of Sundays left in the month */
 
-                        d = d + 7 * n;  /* mday of final Sunday */
+                        d = d + 7 * n;  /* d: mday of final Sunday */
 
         if              (month == MARCH) {
-            if (d < mday)
+            if (mday < d) /* before last Sunday */
                 return 0;
-            if (d > mday)
+            if (mday > d) /* past last Sunday */
                 return ONE_HOUR;
-            if (hour < 2)
+            if (hour < 2) /* at last Sunday, before switching */
                 return 0;
-            return ONE_HOUR;
+            return ONE_HOUR; /* at last Sunday, after switching */
         }
-        if              (d < mday)
+       /* month == OCTOBER */
+        if              (mday < d) /* before last Sunday */
                             return ONE_HOUR;
-        if              (d > mday)
+        if              (mday > d) /* past last Sunday */
                             return 0;
-        if              (hour < 2)
+        if              (hour < 2) /* at last Sunday, before switching */
                             return ONE_HOUR;
-                        return 0;
+                        return 0; /* at last Sunday, after switchin */
 
     }