[PATCH 2/3] time/tst-strftime2.c: Make the file easier to maintain.

[Rafal Luzynski <digitalfreak at lingonborough dot com>]

Express the years as full Gregorian years (e.g., 1988 instead of 88)
and months with natural numbers (1-12 rather than 0-11).

Compare actual dates rather than indexes when selecting the era name.

Declare the local variable era as a string character pointer rather than
an array of chars where the actual string is copied which might lead to
potential buffer overflows in future.

	* time/tst-strftime2.c (date_t): Explicitly define the type.
	(dates): Use natural month and year numbers to express a date.
	(is_before): New function to compare dates.
	(mkreftable): Minor improvements to simplify maintenance.
	(do_test): Reflect the changes in dates array.
---
 time/tst-strftime2.c | 62
+++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 44 insertions(+), 18 deletions(-)

diff --git a/time/tst-strftime2.c b/time/tst-strftime2.c
index 3dca2a9..bf5a66d 100644
--- a/time/tst-strftime2.c
+++ b/time/tst-strftime2.c
@@ -19,8 +19,10 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include <array_length.h>
+#include <assert.h>
 #include <locale.h>
 #include <time.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
 
@@ -28,27 +30,44 @@ static const char *locales[] = { "ja_JP.UTF-8",
"lo_LA.UTF-8", "th_TH.UTF-8" };
 
 static const char *formats[] = { "%EY", "%_EY", "%-EY" };
 
-static const struct
+typedef struct
 {
   const int d, m, y;
-} dates[] =
+} date_t;
+
+static const date_t dates[] =
   {
-    { 1, 3, 88 },
-    { 7, 0, 89 },
-    { 8, 0, 89 },
-    { 1, 3, 90 },
-    { 1, 3, 97 },
-    { 1, 3, 98 }
+    { 1, 4, 1988 },
+    { 7, 1, 1989 },
+    { 8, 1, 1989 },
+    { 1, 4, 1990 },
+    { 1, 4, 1997 },
+    { 1, 4, 1998 }
   };
 
 static char ref[array_length (locales)][array_length (formats)]
 	       [array_length (dates)][100];
 
+static bool
+is_before (const date_t *date, const int d, const int m, const int y)
+{
+  if (date->y < y)
+    return true;
+  else if (date->y > y)
+    return false;
+  else if (date->m < m)
+    return true;
+  else if (date->m > m)
+    return false;
+  else
+    return date->d < d;
+}
+
 static void
 mkreftable (void)
 {
   int i, j, k;
-  char era[10];
+  const char *era;
   static const int yrj[] = { 63, 64, 1, 2, 9, 10 };
   static const int yrb[] = { 2531, 2532, 2532, 2533, 2540, 2541 };
 
@@ -56,10 +75,13 @@ mkreftable (void)
     for (j = 0; j < array_length (formats); j++)
       for (k = 0; k < array_length (dates); k++)
 	{
-	  if (i == 0)
+	  if (i == 0)  /* ja_JP  */
 	    {
-	      sprintf (era, "%s", (k < 2) ? "\xe6\x98\xad\xe5\x92\x8c"
-					  : "\xe5\xb9\xb3\xe6\x88\x90");
+	      if (is_before (&dates[k], 8, 1, 1989))
+		era = "\xe6\x98\xad\xe5\x92\x8c";
+	      else
+		era = "\xe5\xb9\xb3\xe6\x88\x90";
+
 	      if (yrj[k] == 1)
 		sprintf (ref[i][j][k], "%s\xe5\x85\x83\xe5\xb9\xb4", era);
 	      else
@@ -72,16 +94,20 @@ mkreftable (void)
 		    sprintf (ref[i][j][k], "%s%d\xe5\xb9\xb4", era, yrj[k]);
 		}
 	    }
-	  else if (i == 1)
+	  else if (i == 1)  /* lo_LA  */
 	    {
-	      sprintf (era, "\xe0\xba\x9e\x2e\xe0\xba\xaa\x2e ");
+	      era = "\xe0\xba\x9e\x2e\xe0\xba\xaa\x2e ";
 	      sprintf (ref[i][j][k], "%s%d", era, yrb[k]);
 	    }
-	  else
+	  else if (i == 2)  /* th_TH  */
 	    {
-	      sprintf (era, "\xe0\xb8\x9e\x2e\xe0\xb8\xa8\x2e ");
+	      era = "\xe0\xb8\x9e\x2e\xe0\xb8\xa8\x2e ";
 	      sprintf (ref[i][j][k], "%s%d", era, yrb[k]);
 	    }
+	  else
+	    {
+	      assert (0);  /* Unreachable.  */
+	    }
 	}
 }
 
@@ -107,8 +133,8 @@ do_test (void)
 	  for (k = 0; k < array_length (dates); k++)
 	    {
 	      ttm.tm_mday = dates[k].d;
-	      ttm.tm_mon  = dates[k].m;
-	      ttm.tm_year = dates[k].y;
+	      ttm.tm_mon  = dates[k].m - 1;
+	      ttm.tm_year = dates[k].y - 1900;
 	      strftime (date, sizeof (date), "%F", &ttm);
 	      r = strftime (buf, sizeof (buf), formats[j], &ttm);
 	      e = strlen (ref[i][j][k]);
-- 
2.7.5