Fix for pg_upgrade's forcing pg_controldata into English

Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > Greg Sabino Mullane wrote:
> >> Specifically, LANGUAGE changes the headers of pg_controldata
> >> (but not the actual output, LC_ALL does that). Thanks for the
> >> nudge, I'll get to rewriting some code.
>
> > pg_upgrade does this in controldata.c for this exact reason:
>
> >         /*
> >          * Because we test the pg_resetxlog output strings, it has to be in
> >          * English.
> >          */
> >         if (getenv("LANG"))
> >             lang = pg_strdup(ctx, getenv("LANG"));
> >     #ifndef WIN32
> >         putenv(pg_strdup(ctx, "LANG=C"));
> >     #else
> >         SetEnvironmentVariableA("LANG", "C");
> >     #endif
>
> You do realize that's far from bulletproof?  To be sure that that does
> anything, you'd need to set (or unset) LC_ALL and LC_MESSAGES as well.
> And I thought Windows spelled it LANGUAGE not LANG ...

I have implemented your suggestion of setting LANG, LANGUAGE, and
LC_MESSAGES based on code in pg_regress.c;  that is the only place I see
where we force English, and it certainly has received more testing.

Should I set LC_ALL too?  The other variables mentioned in pg_regress.c?
Is this something I should patch to 9.0.X?

Patch attached.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +
Index: contrib/pg_upgrade/controldata.c
===================================================================
RCS file: /cvsroot/pgsql/contrib/pg_upgrade/controldata.c,v
retrieving revision 1.9
diff -c -c -r1.9 controldata.c
*** contrib/pg_upgrade/controldata.c    6 Jul 2010 19:18:55 -0000    1.9
--- contrib/pg_upgrade/controldata.c    1 Sep 2010 20:30:45 -0000
***************
*** 11,16 ****
--- 11,17 ----

  #include <ctype.h>

+ static void putenv2(migratorContext *ctx, const char *var, const char *val);

  /*
   * get_control_data()
***************
*** 52,69 ****
      bool        got_date_is_int = false;
      bool        got_float8_pass_by_value = false;
      char       *lang = NULL;

      /*
!      * Because we test the pg_resetxlog output strings, it has to be in
!      * English.
       */
      if (getenv("LANG"))
          lang = pg_strdup(ctx, getenv("LANG"));
  #ifndef WIN32
!     putenv(pg_strdup(ctx, "LANG=C"));
  #else
!     SetEnvironmentVariableA("LANG", "C");
  #endif
      snprintf(cmd, sizeof(cmd), SYSTEMQUOTE "\"%s/%s \"%s\"" SYSTEMQUOTE,
               cluster->bindir,
               live_check ? "pg_controldata\"" : "pg_resetxlog\" -n",
--- 53,82 ----
      bool        got_date_is_int = false;
      bool        got_float8_pass_by_value = false;
      char       *lang = NULL;
+     char       *language = NULL;
+     char       *lc_messages = NULL;

      /*
!      * Because we test the pg_resetxlog output as strings, it has to be in
!      * English.  Copied from pg_regress.c.
       */
      if (getenv("LANG"))
          lang = pg_strdup(ctx, getenv("LANG"));
+     if (getenv("LANGUAGE"))
+         language = pg_strdup(ctx, getenv("LANGUAGE"));
+     if (getenv("LC_MESSAGES"))
+         lc_messages = pg_strdup(ctx, getenv("LC_MESSAGES"));
+
+     putenv2(ctx, "LANG",
  #ifndef WIN32
!             NULL);
  #else
!             /* On Windows the default locale cannot be English, so force it */
!             "en");
  #endif
+     putenv2(ctx, "LANGUAGE", NULL);
+     putenv2(ctx, "LC_MESSAGES", "C");
+
      snprintf(cmd, sizeof(cmd), SYSTEMQUOTE "\"%s/%s \"%s\"" SYSTEMQUOTE,
               cluster->bindir,
               live_check ? "pg_controldata\"" : "pg_resetxlog\" -n",
***************
*** 334,361 ****
      if (output)
          pclose(output);

!     /* restore LANG */
!     if (lang)
!     {
! #ifndef WIN32
!         char       *envstr = (char *) pg_malloc(ctx, strlen(lang) + 6);
!
!         sprintf(envstr, "LANG=%s", lang);
!         putenv(envstr);
! #else
!         SetEnvironmentVariableA("LANG", lang);
! #endif
!         pg_free(lang);
!     }
!     else
!     {
! #ifndef WIN32
!         unsetenv("LANG");
! #else
!         SetEnvironmentVariableA("LANG", "");
! #endif
!     }
!
      /* verify that we got all the mandatory pg_control data */
      if (!got_xid || !got_oid ||
          (!live_check && !got_log_id) ||
--- 347,360 ----
      if (output)
          pclose(output);

!     /* restore environment variable settings */
!     putenv2(ctx, "LANG", lang);
!     putenv2(ctx, "LANGUAGE", language);
!     putenv2(ctx, "LC_MESSAGES", lc_messages);
!     pg_free(lang);
!     pg_free(language);
!     pg_free(lc_messages);
!
      /* verify that we got all the mandatory pg_control data */
      if (!got_xid || !got_oid ||
          (!live_check && !got_log_id) ||
***************
*** 492,494 ****
--- 491,524 ----
          pg_log(ctx, PG_FATAL, "Unable to rename %s to %s.\n", old_path, new_path);
      check_ok(ctx);
  }
+
+
+ /*
+  *    This is like putenv(), but takes two arguments
+  *    It also does unsetenv() if val is NULL.
+  */
+ static void
+ putenv2(migratorContext *ctx, const char *var, const char *val)
+ {
+     if (val)
+     {
+ #ifndef WIN32
+         char       *envstr = (char *) pg_malloc(ctx, strlen(var) +
+                                                 strlen(val) + 1);
+
+         sprintf(envstr, "%s=%s", var, val);
+         putenv(envstr);
+         pg_free(envstr);
+ #else
+         SetEnvironmentVariableA(var, val);
+ #endif
+     }
+     else
+     {
+ #ifndef WIN32
+         unsetenv(var);
+ #else
+         SetEnvironmentVariableA(var, "");
+ #endif
+     }
+ }