1 /*
2 ** Based on the UCB version with the copyright notice and sccsid
3 ** appearing below.
4 **
5 ** This is ANSIish only when "multibyte character == plain character".
6 */
7 
8 #include "private.h"
9 
10 /*
11 ** Copyright (c) 1989 The Regents of the University of California.
12 ** All rights reserved.
13 **
14 ** Redistribution and use in source and binary forms are permitted
15 ** provided that the above copyright notice and this paragraph are
16 ** duplicated in all such forms and that any documentation,
17 ** advertising materials, and other materials related to such
18 ** distribution and use acknowledge that the software was developed
19 ** by the University of California, Berkeley. The name of the
20 ** University may not be used to endorse or promote products derived
21 ** from this software without specific prior written permission.
22 ** THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
23 ** IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
24 ** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
25 */
26 
27 #include "tzfile.h"
28 #include "fcntl.h"
29 #include "locale.h"
30 
31 #if __ANDROID__
32 
33 /* LP32 had a 32-bit time_t, so we need to work around that here. */
34 #if defined(__LP64__)
35 #define time64_t time_t
36 #define mktime64 mktime
37 #else
38 #include <time64.h>
39 #endif
40 
41 #include <ctype.h>
42 
43 #endif
44 
45 struct lc_time_T {
46     const char *    mon[MONSPERYEAR];
47     const char *    month[MONSPERYEAR];
48     const char *    wday[DAYSPERWEEK];
49     const char *    weekday[DAYSPERWEEK];
50     const char *    X_fmt;
51     const char *    x_fmt;
52     const char *    c_fmt;
53     const char *    am;
54     const char *    pm;
55     const char *    date_fmt;
56 };
57 
58 #ifdef LOCALE_HOME
59 #include "sys/stat.h"
60 static struct lc_time_T                localebuf;
61 static struct lc_time_T *      _loc(void);
62 #define Locale _loc()
63 #endif /* defined LOCALE_HOME */
64 #ifndef LOCALE_HOME
65 #define Locale  (&C_time_locale)
66 #endif /* !defined LOCALE_HOME */
67 
68 static const struct lc_time_T   C_time_locale = {
69     {
70         "Jan", "Feb", "Mar", "Apr", "May", "Jun",
71         "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
72     }, {
73         "January", "February", "March", "April", "May", "June",
74         "July", "August", "September", "October", "November", "December"
75     }, {
76         "Sun", "Mon", "Tue", "Wed",
77         "Thu", "Fri", "Sat"
78     }, {
79         "Sunday", "Monday", "Tuesday", "Wednesday",
80         "Thursday", "Friday", "Saturday"
81     },
82 
83     /* X_fmt */
84     "%H:%M:%S",
85 
86     /*
87     ** x_fmt
88     ** C99 requires this format.
89     ** Using just numbers (as here) makes Quakers happier;
90     ** it's also compatible with SVR4.
91     */
92     "%m/%d/%y",
93 
94     /*
95     ** c_fmt
96     ** C99 requires this format.
97     ** Previously this code used "%D %X", but we now conform to C99.
98     ** Note that
99     **  "%a %b %d %H:%M:%S %Y"
100     ** is used by Solaris 2.3.
101     */
102     "%a %b %e %T %Y",
103 
104     /* am */
105     "AM",
106 
107     /* pm */
108     "PM",
109 
110     /* date_fmt */
111     "%a %b %e %H:%M:%S %Z %Y"
112 };
113 
114 static char *   _add(const char *, char *, const char *, int);
115 static char *   _conv(int, const char *, char *, const char *);
116 static char *   _fmt(const char *, const struct tm *, char *, const char *,
117             int *);
118 static char *   _yconv(int, int, int, int, char *, const char *, int);
119 static char *   getformat(int, char *, char *, char *, char *);
120 
121 extern char *   tzname[];
122 
123 #ifndef YEAR_2000_NAME
124 #define YEAR_2000_NAME  "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
125 #endif /* !defined YEAR_2000_NAME */
126 
127 #define IN_NONE 0
128 #define IN_SOME 1
129 #define IN_THIS 2
130 #define IN_ALL  3
131 
132 #define FORCE_LOWER_CASE 0x100
133 
134 size_t
strftime(char * const s,const size_t maxsize,const char * const format,const struct tm * const t)135 strftime(char * const s, const size_t maxsize, const char *const format,
136         const struct tm *const t)
137 {
138     char *  p;
139     int warn;
140 
141     tzset();
142 #ifdef LOCALE_HOME
143     localebuf.mon[0] = 0;
144 #endif /* defined LOCALE_HOME */
145     warn = IN_NONE;
146     p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn);
147 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
148     if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
149         (void) fprintf(stderr, "\n");
150         if (format == NULL)
151             (void) fprintf(stderr, "NULL strftime format ");
152         else    (void) fprintf(stderr, "strftime format \"%s\" ",
153                 format);
154         (void) fprintf(stderr, "yields only two digits of years in ");
155         if (warn == IN_SOME)
156             (void) fprintf(stderr, "some locales");
157         else if (warn == IN_THIS)
158             (void) fprintf(stderr, "the current locale");
159         else    (void) fprintf(stderr, "all locales");
160         (void) fprintf(stderr, "\n");
161     }
162 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
163     if (p == s + maxsize)
164         return 0;
165     *p = '\0';
166     return p - s;
167 }
168 
getformat(int modifier,char * normal,char * underscore,char * dash,char * zero)169 static char *getformat(int modifier, char *normal, char *underscore,
170                        char *dash, char *zero) {
171     switch (modifier) {
172     case '_':
173         return underscore;
174 
175     case '-':
176         return dash;
177 
178     case '0':
179         return zero;
180     }
181 
182     return normal;
183 }
184 
185 static char *
_fmt(const char * format,const struct tm * const t,char * pt,const char * const ptlim,int * warnp)186 _fmt(const char *format, const struct tm *const t, char * pt,
187         const char *const ptlim, int *warnp)
188 {
189     for ( ; *format; ++format) {
190         if (*format == '%') {
191             int modifier = 0;
192 label:
193             switch (*++format) {
194             case '\0':
195                 --format;
196                 break;
197             case 'A':
198                 pt = _add((t->tm_wday < 0 ||
199                     t->tm_wday >= DAYSPERWEEK) ?
200                     "?" : Locale->weekday[t->tm_wday],
201                     pt, ptlim, modifier);
202                 continue;
203             case 'a':
204                 pt = _add((t->tm_wday < 0 ||
205                     t->tm_wday >= DAYSPERWEEK) ?
206                     "?" : Locale->wday[t->tm_wday],
207                     pt, ptlim, modifier);
208                 continue;
209             case 'B':
210                 pt = _add((t->tm_mon < 0 ||
211                                 t->tm_mon >= MONSPERYEAR) ?
212                                 "?" : Locale->month[t->tm_mon],
213                                 pt, ptlim, modifier);
214                 continue;
215             case 'b':
216             case 'h':
217                 pt = _add((t->tm_mon < 0 ||
218                     t->tm_mon >= MONSPERYEAR) ?
219                     "?" : Locale->mon[t->tm_mon],
220                     pt, ptlim, modifier);
221                 continue;
222             case 'C':
223                 /*
224                 ** %C used to do a...
225                 **  _fmt("%a %b %e %X %Y", t);
226                 ** ...whereas now POSIX 1003.2 calls for
227                 ** something completely different.
228                 ** (ado, 1993-05-24)
229                 */
230                 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
231                     pt, ptlim, modifier);
232                 continue;
233             case 'c':
234                 {
235                 int warn2 = IN_SOME;
236 
237                 pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2);
238                 if (warn2 == IN_ALL)
239                     warn2 = IN_THIS;
240                 if (warn2 > *warnp)
241                     *warnp = warn2;
242                 }
243                 continue;
244             case 'D':
245                                 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp);
246                 continue;
247             case 'd':
248                                 pt = _conv(t->tm_mday,
249                                            getformat(modifier, "%02d",
250                                                      "%2d", "%d", "%02d"),
251                                            pt, ptlim);
252                 continue;
253             case 'E':
254             case 'O':
255                 /*
256                 ** C99 locale modifiers.
257                 ** The sequences
258                 **  %Ec %EC %Ex %EX %Ey %EY
259                 **  %Od %oe %OH %OI %Om %OM
260                 **  %OS %Ou %OU %OV %Ow %OW %Oy
261                 ** are supposed to provide alternate
262                 ** representations.
263                 */
264                 goto label;
265             case '_':
266             case '-':
267             case '0':
268             case '^':
269             case '#':
270                 modifier = *format;
271                 goto label;
272             case 'e':
273                 pt = _conv(t->tm_mday,
274                                            getformat(modifier, "%2d",
275                                                      "%2d", "%d", "%02d"),
276                                            pt, ptlim);
277                 continue;
278             case 'F':
279                 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp);
280                 continue;
281             case 'H':
282                 pt = _conv(t->tm_hour,
283                                            getformat(modifier, "%02d",
284                                                      "%2d", "%d", "%02d"),
285                                            pt, ptlim);
286                 continue;
287             case 'I':
288                 pt = _conv((t->tm_hour % 12) ?
289                     (t->tm_hour % 12) : 12,
290                     getformat(modifier, "%02d",
291                                                   "%2d", "%d", "%02d"),
292                                         pt, ptlim);
293                 continue;
294             case 'j':
295                 pt = _conv(t->tm_yday + 1,
296                            getformat(modifier, "%03d", "%3d", "%d", "%03d"),
297                            pt, ptlim);
298                 continue;
299             case 'k':
300                 /*
301                 ** This used to be...
302                 **  _conv(t->tm_hour % 12 ?
303                 **      t->tm_hour % 12 : 12, 2, ' ');
304                 ** ...and has been changed to the below to
305                 ** match SunOS 4.1.1 and Arnold Robbins'
306                 ** strftime version 3.0. That is, "%k" and
307                 ** "%l" have been swapped.
308                 ** (ado, 1993-05-24)
309                 */
310                 pt = _conv(t->tm_hour,
311                                            getformat(modifier, "%2d",
312                                                      "%2d", "%d", "%02d"),
313                                            pt, ptlim);
314                 continue;
315 #ifdef KITCHEN_SINK
316             case 'K':
317                 /*
318                 ** After all this time, still unclaimed!
319                 */
320                 pt = _add("kitchen sink", pt, ptlim);
321                 continue;
322 #endif /* defined KITCHEN_SINK */
323             case 'l':
324                 /*
325                 ** This used to be...
326                 **  _conv(t->tm_hour, 2, ' ');
327                 ** ...and has been changed to the below to
328                 ** match SunOS 4.1.1 and Arnold Robbin's
329                 ** strftime version 3.0. That is, "%k" and
330                 ** "%l" have been swapped.
331                 ** (ado, 1993-05-24)
332                 */
333                 pt = _conv((t->tm_hour % 12) ?
334                     (t->tm_hour % 12) : 12,
335                     getformat(modifier, "%2d",
336                                                   "%2d", "%d", "%02d"),
337                                         pt, ptlim);
338                 continue;
339             case 'M':
340                 pt = _conv(t->tm_min,
341                                            getformat(modifier, "%02d",
342                                                      "%2d", "%d", "%02d"),
343                                            pt, ptlim);
344                 continue;
345             case 'm':
346                 pt = _conv(t->tm_mon + 1,
347                                            getformat(modifier, "%02d",
348                                                      "%2d", "%d", "%02d"),
349                                            pt, ptlim);
350                 continue;
351             case 'n':
352                 pt = _add("\n", pt, ptlim, modifier);
353                 continue;
354             case 'p':
355                 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
356                     Locale->pm :
357                     Locale->am,
358                     pt, ptlim, modifier);
359                 continue;
360             case 'P':
361                 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
362                     Locale->pm :
363                     Locale->am,
364                     pt, ptlim, FORCE_LOWER_CASE);
365                 continue;
366             case 'R':
367                 pt = _fmt("%H:%M", t, pt, ptlim, warnp);
368                 continue;
369             case 'r':
370                 pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp);
371                 continue;
372             case 'S':
373                 pt = _conv(t->tm_sec,
374                                            getformat(modifier, "%02d",
375                                                      "%2d", "%d", "%02d"),
376                                            pt, ptlim);
377                 continue;
378             case 's':
379                 {
380                     struct tm   tm;
381                     char        buf[INT_STRLEN_MAXIMUM(
382                                 time64_t) + 1];
383                     time64_t    mkt;
384 
385                     tm = *t;
386                     mkt = mktime64(&tm);
387                     if (TYPE_SIGNED(time64_t))
388                         (void) snprintf(buf, sizeof(buf), "%lld",
389                             (long long) mkt);
390                     else    (void) snprintf(buf, sizeof(buf), "%llu",
391                             (unsigned long long) mkt);
392                     pt = _add(buf, pt, ptlim, modifier);
393                 }
394                 continue;
395             case 'T':
396                 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp);
397                 continue;
398             case 't':
399                 pt = _add("\t", pt, ptlim, modifier);
400                 continue;
401             case 'U':
402                 pt = _conv((t->tm_yday + DAYSPERWEEK -
403                     t->tm_wday) / DAYSPERWEEK,
404                     getformat(modifier, "%02d",
405                                                   "%2d", "%d", "%02d"),
406                                         pt, ptlim);
407                 continue;
408             case 'u':
409                 /*
410                 ** From Arnold Robbins' strftime version 3.0:
411                 ** "ISO 8601: Weekday as a decimal number
412                 ** [1 (Monday) - 7]"
413                 ** (ado, 1993-05-24)
414                 */
415                 pt = _conv((t->tm_wday == 0) ?
416                     DAYSPERWEEK : t->tm_wday, "%d", pt, ptlim);
417                 continue;
418             case 'V':   /* ISO 8601 week number */
419             case 'G':   /* ISO 8601 year (four digits) */
420             case 'g':   /* ISO 8601 year (two digits) */
421 /*
422 ** From Arnold Robbins' strftime version 3.0: "the week number of the
423 ** year (the first Monday as the first day of week 1) as a decimal number
424 ** (01-53)."
425 ** (ado, 1993-05-24)
426 **
427 ** From <http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html> by Markus Kuhn:
428 ** "Week 01 of a year is per definition the first week which has the
429 ** Thursday in this year, which is equivalent to the week which contains
430 ** the fourth day of January. In other words, the first week of a new year
431 ** is the week which has the majority of its days in the new year. Week 01
432 ** might also contain days from the previous year and the week before week
433 ** 01 of a year is the last week (52 or 53) of the previous year even if
434 ** it contains days from the new year. A week starts with Monday (day 1)
435 ** and ends with Sunday (day 7). For example, the first week of the year
436 ** 1997 lasts from 1996-12-30 to 1997-01-05..."
437 ** (ado, 1996-01-02)
438 */
439                 {
440                     int year;
441                     int base;
442                     int yday;
443                     int wday;
444                     int w;
445 
446                     year = t->tm_year;
447                     base = TM_YEAR_BASE;
448                     yday = t->tm_yday;
449                     wday = t->tm_wday;
450                     for ( ; ; ) {
451                         int len;
452                         int bot;
453                         int top;
454 
455                         len = isleap_sum(year, base) ?
456                             DAYSPERLYEAR :
457                             DAYSPERNYEAR;
458                         /*
459                         ** What yday (-3 ... 3) does
460                         ** the ISO year begin on?
461                         */
462                         bot = ((yday + 11 - wday) %
463                             DAYSPERWEEK) - 3;
464                         /*
465                         ** What yday does the NEXT
466                         ** ISO year begin on?
467                         */
468                         top = bot -
469                             (len % DAYSPERWEEK);
470                         if (top < -3)
471                             top += DAYSPERWEEK;
472                         top += len;
473                         if (yday >= top) {
474                             ++base;
475                             w = 1;
476                             break;
477                         }
478                         if (yday >= bot) {
479                             w = 1 + ((yday - bot) /
480                                 DAYSPERWEEK);
481                             break;
482                         }
483                         --base;
484                         yday += isleap_sum(year, base) ?
485                             DAYSPERLYEAR :
486                             DAYSPERNYEAR;
487                     }
488 #ifdef XPG4_1994_04_09
489                     if ((w == 52 &&
490                         t->tm_mon == TM_JANUARY) ||
491                         (w == 1 &&
492                         t->tm_mon == TM_DECEMBER))
493                             w = 53;
494 #endif /* defined XPG4_1994_04_09 */
495                     if (*format == 'V')
496                         pt = _conv(w,
497                                 getformat(modifier, "%02d", "%2d", "%d", "%02d"),
498                                pt, ptlim);
499                     else if (*format == 'g') {
500                         *warnp = IN_ALL;
501                         pt = _yconv(year, base, 0, 1,
502                             pt, ptlim, modifier);
503                     } else  pt = _yconv(year, base, 1, 1,
504                             pt, ptlim, modifier);
505                 }
506                 continue;
507             case 'v':
508                 /*
509                 ** From Arnold Robbins' strftime version 3.0:
510                 ** "date as dd-bbb-YYYY"
511                 ** (ado, 1993-05-24)
512                 */
513                 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp);
514                 continue;
515             case 'W':
516                 pt = _conv((t->tm_yday + DAYSPERWEEK -
517                     (t->tm_wday ?
518                     (t->tm_wday - 1) :
519                     (DAYSPERWEEK - 1))) / DAYSPERWEEK,
520                     getformat(modifier, "%02d",
521                                                   "%2d", "%d", "%02d"),
522                                         pt, ptlim);
523                 continue;
524             case 'w':
525                 pt = _conv(t->tm_wday, "%d", pt, ptlim);
526                 continue;
527             case 'X':
528                 pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp);
529                 continue;
530             case 'x':
531                 {
532                 int warn2 = IN_SOME;
533 
534                 pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2);
535                 if (warn2 == IN_ALL)
536                     warn2 = IN_THIS;
537                 if (warn2 > *warnp)
538                     *warnp = warn2;
539                 }
540                 continue;
541             case 'y':
542                 *warnp = IN_ALL;
543                 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
544                     pt, ptlim, modifier);
545                 continue;
546             case 'Y':
547                 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
548                     pt, ptlim, modifier);
549                 continue;
550             case 'Z':
551 #ifdef TM_ZONE
552                 if (t->TM_ZONE != NULL)
553                     pt = _add(t->TM_ZONE, pt, ptlim,
554                                                   modifier);
555                 else
556 #endif /* defined TM_ZONE */
557                 if (t->tm_isdst >= 0)
558                     pt = _add(tzname[t->tm_isdst != 0],
559                         pt, ptlim, modifier);
560                 /*
561                 ** C99 says that %Z must be replaced by the
562                 ** empty string if the time zone is not
563                 ** determinable.
564                 */
565                 continue;
566             case 'z':
567                 {
568                 long     diff;
569                 char const *    sign;
570 
571                 if (t->tm_isdst < 0)
572                     continue;
573 #ifdef TM_GMTOFF
574                 diff = t->TM_GMTOFF;
575 #else /* !defined TM_GMTOFF */
576                 /*
577                 ** C99 says that the UT offset must
578                 ** be computed by looking only at
579                 ** tm_isdst. This requirement is
580                 ** incorrect, since it means the code
581                 ** must rely on magic (in this case
582                 ** altzone and timezone), and the
583                 ** magic might not have the correct
584                 ** offset. Doing things correctly is
585                 ** tricky and requires disobeying C99;
586                 ** see GNU C strftime for details.
587                 ** For now, punt and conform to the
588                 ** standard, even though it's incorrect.
589                 **
590                 ** C99 says that %z must be replaced by the
591                 ** empty string if the time zone is not
592                 ** determinable, so output nothing if the
593                 ** appropriate variables are not available.
594                 */
595                 if (t->tm_isdst == 0)
596 #ifdef USG_COMPAT
597                     diff = -timezone;
598 #else /* !defined USG_COMPAT */
599                     continue;
600 #endif /* !defined USG_COMPAT */
601                 else
602 #ifdef ALTZONE
603                     diff = -altzone;
604 #else /* !defined ALTZONE */
605                     continue;
606 #endif /* !defined ALTZONE */
607 #endif /* !defined TM_GMTOFF */
608                 if (diff < 0) {
609                     sign = "-";
610                     diff = -diff;
611                 } else  sign = "+";
612                 pt = _add(sign, pt, ptlim, modifier);
613                 diff /= SECSPERMIN;
614                 diff = (diff / MINSPERHOUR) * 100 +
615                     (diff % MINSPERHOUR);
616                 pt = _conv(diff,
617                                            getformat(modifier, "%04d",
618                                                      "%4d", "%d", "%04d"),
619                                            pt, ptlim);
620                 }
621                 continue;
622             case '+':
623                 pt = _fmt(Locale->date_fmt, t, pt, ptlim,
624                     warnp);
625                 continue;
626             case '%':
627             /*
628             ** X311J/88-090 (4.12.3.5): if conversion char is
629             ** undefined, behavior is undefined. Print out the
630             ** character itself as printf(3) also does.
631             */
632             default:
633                 break;
634             }
635         }
636         if (pt == ptlim)
637             break;
638         *pt++ = *format;
639     }
640     return pt;
641 }
642 
643 static char *
_conv(const int n,const char * const format,char * const pt,const char * const ptlim)644 _conv(const int n, const char *const format, char *const pt,
645         const char *const ptlim)
646 {
647     char    buf[INT_STRLEN_MAXIMUM(int) + 1];
648 
649     (void) snprintf(buf, sizeof(buf), format, n);
650     return _add(buf, pt, ptlim, 0);
651 }
652 
653 static char *
_add(const char * str,char * pt,const char * const ptlim,int modifier)654 _add(const char *str, char *pt, const char *const ptlim, int modifier)
655 {
656         int c;
657 
658         switch (modifier) {
659         case FORCE_LOWER_CASE:
660                 while (pt < ptlim && (*pt = tolower(*str++)) != '\0') {
661                         ++pt;
662                 }
663                 break;
664 
665         case '^':
666                 while (pt < ptlim && (*pt = toupper(*str++)) != '\0') {
667                         ++pt;
668                 }
669                 break;
670 
671         case '#':
672                 while (pt < ptlim && (c = *str++) != '\0') {
673                         if (isupper(c)) {
674                                 c = tolower(c);
675                         } else if (islower(c)) {
676                                 c = toupper(c);
677                         }
678                         *pt = c;
679                         ++pt;
680                 }
681 
682                 break;
683 
684         default:
685                 while (pt < ptlim && (*pt = *str++) != '\0') {
686                         ++pt;
687                 }
688         }
689 
690     return pt;
691 }
692 
693 /*
694 ** POSIX and the C Standard are unclear or inconsistent about
695 ** what %C and %y do if the year is negative or exceeds 9999.
696 ** Use the convention that %C concatenated with %y yields the
697 ** same output as %Y, and that %Y contains at least 4 bytes,
698 ** with more only if necessary.
699 */
700 
701 static char *
_yconv(const int a,const int b,const int convert_top,const int convert_yy,char * pt,const char * const ptlim,int modifier)702 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
703         char *pt, const char *const ptlim, int modifier)
704 {
705     register int    lead;
706     register int    trail;
707 
708 #define DIVISOR 100
709     trail = a % DIVISOR + b % DIVISOR;
710     lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
711     trail %= DIVISOR;
712     if (trail < 0 && lead > 0) {
713         trail += DIVISOR;
714         --lead;
715     } else if (lead < 0 && trail > 0) {
716         trail -= DIVISOR;
717         ++lead;
718     }
719     if (convert_top) {
720         if (lead == 0 && trail < 0)
721             pt = _add("-0", pt, ptlim, modifier);
722         else    pt = _conv(lead, getformat(modifier, "%02d", "%2d", "%d", "%02d"), pt, ptlim);
723     }
724     if (convert_yy)
725         pt = _conv(((trail < 0) ? -trail : trail), getformat(modifier, "%02d", "%2d", "%d", "%02d"), pt, ptlim);
726     return pt;
727 }
728