[ptime] fix PM offset

Fixes #517

src/Makefile.am

@@ -75,6 +75,9 @@ TIME_FORMATS = \
     "%b %e, %Y %l:%M:%S %p" \
     "%m/%d/%y %H:%M:%S" \
     "%m/%d/%Y %I:%M:%S:%L %p %Z" \
+    "%m/%d/%Y %I:%M:%S %p %Z" \
+    "%m/%d/%Y %l:%M:%S %p %Z" \
+    "%m/%e/%Y %I:%M:%S %p" \
     "%m/%e/%Y %l:%M:%S %p" \
     "%d/%b/%y %H:%M:%S" \
     "%m%d %H:%M:%S" \

src/ptimec.hh

@@ -635,7 +635,9 @@ inline bool ptime_p(struct exttm *dst, const char *str, off_t &off_inout, ssize_
         else if ((lead & 0xdf) == 'A') {
         }
         else if ((lead & 0xdf) == 'P') {
-            dst->et_tm.tm_hour += 12;
+            if (dst->et_tm.tm_hour > 12) {
+                dst->et_tm.tm_hour += 12;
+            }
         }
         else {
             return false;

test/test_date_time_scanner.cc

@@ -40,6 +40,7 @@ static const char *GOOD_TIMES[] = {
     "May 01 00:00:01",
     "May 10 12:00:01",
     "2014-02-11 16:12:34",
+    "05/18/2018 12:00:53 PM",
 
     NULL
 };
@@ -71,6 +72,7 @@ int main(int argc, char *argv[])
 
         char ts[64];
 
+        gmtime_r(&tv.tv_sec, &tm.et_tm);
         dts.ftime(ts, sizeof(ts), tm);
         printf("orig %s\n", GOOD_TIMES[lpc]);
         printf("loop %s\n", ts);