v2-0003-Revert-Blind-attempt-to-fix-_configthreadlocale-f.patch

From 4c94af123a38c8c68178497f7b59e1d948f2d9ca Mon Sep 17 00:00:00 2001
From: Thomas Munro <tmunro@postgresql.org>
Date: Sat, 23 Nov 2024 09:43:16 +1300
Subject: [PATCH v2 3/3] Revert "Blind attempt to fix _configthreadlocale()
 failures on MinGW."

This reverts commit 2cf91ccb73ce888c44e3751548fb7c77e87335f2.

When using the old msvcrt.dll, MinGW would supply its own dummy version
of _configthreadlocale() that just returns -1 if you try to use it.  For
a time we tolerated that to shut the build farm up.  We would fall back
to code that was enough for the tests to pass, but it would have crashed
a real multithreaded program though, so it was bogus.

We don't need that kludge anymore, because we require ucrt (the modern
Windows C runtime).  We expect the real _configthreadlocale() to be
present, and the ECPG tests will now fail if it isn't.  The workaround
was dead code and it's time to revert it.

Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/d9e7731c-ca1b-477c-9298-fa51e135574a%40eisentraut.org
---
 src/interfaces/ecpg/ecpglib/descriptor.c |  2 +-
 src/interfaces/ecpg/ecpglib/execute.c    | 20 +++++++++-----------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/src/interfaces/ecpg/ecpglib/descriptor.c b/src/interfaces/ecpg/ecpglib/descriptor.c
index 56e2bc4153..aee888432f 100644
--- a/src/interfaces/ecpg/ecpglib/descriptor.c
+++ b/src/interfaces/ecpg/ecpglib/descriptor.c
@@ -512,7 +512,7 @@ ECPGget_desc(int lineno, const char *desc_name, int index,...)
 		}
 #ifdef WIN32
 		if (stmt.oldthreadlocale != -1)
-			(void) _configthreadlocale(stmt.oldthreadlocale);
+			_configthreadlocale(stmt.oldthreadlocale);
 #endif
 #endif
 	}
diff --git a/src/interfaces/ecpg/ecpglib/execute.c b/src/interfaces/ecpg/ecpglib/execute.c
index 466d5600f9..b5089eac78 100644
--- a/src/interfaces/ecpg/ecpglib/execute.c
+++ b/src/interfaces/ecpg/ecpglib/execute.c
@@ -1977,9 +1977,7 @@ ecpg_do_prologue(int lineno, const int compat, const int force_indicator,
 	 * Make sure we do NOT honor the locale for numeric input/output since the
 	 * database wants the standard decimal point.  If available, use
 	 * uselocale() for this because it's thread-safe.  Windows doesn't have
-	 * that, but it usually does have _configthreadlocale().  In some versions
-	 * of MinGW, _configthreadlocale() exists but always returns -1 --- so
-	 * treat that situation as if the function doesn't exist.
+	 * that, but it does have _configthreadlocale().
 	 */
 #ifdef HAVE_USELOCALE
 
@@ -1997,6 +1995,11 @@ ecpg_do_prologue(int lineno, const int compat, const int force_indicator,
 #else
 #ifdef WIN32
 	stmt->oldthreadlocale = _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+	if (stmt->oldthreadlocale == -1)
+	{
+		ecpg_do_epilogue(stmt);
+		return false;
+	}
 #endif
 	stmt->oldlocale = ecpg_strdup(setlocale(LC_NUMERIC, NULL), lineno);
 	if (stmt->oldlocale == NULL)
@@ -2218,17 +2221,12 @@ ecpg_do_epilogue(struct statement *stmt)
 		uselocale(stmt->oldlocale);
 #else
 	if (stmt->oldlocale)
+	{
 		setlocale(LC_NUMERIC, stmt->oldlocale);
 #ifdef WIN32
-
-	/*
-	 * This is a bit trickier than it looks: if we failed partway through
-	 * statement initialization, oldthreadlocale could still be 0.  But that's
-	 * okay because a call with 0 is defined to be a no-op.
-	 */
-	if (stmt->oldthreadlocale != -1)
-		(void) _configthreadlocale(stmt->oldthreadlocale);
+		_configthreadlocale(stmt->oldthreadlocale);
 #endif
+	}
 #endif
 
 	free_statement(stmt);
-- 
2.47.0