From 7fd551bd72ed917dffe351609e5c4c45daeefb77 Mon Sep 17 00:00:00 2001
From: Ansgar Becker <anse@heidisql.com>
Date: Sun, 28 Jul 2019 08:57:51 +0200
Subject: [PATCH] Give the user a hint to download VC redistributable if
 PostgreSQL dll fails to assign a procedure. See
 https://www.heidisql.com/forum.php?t=18580#p34297

---
 source/dbconnection.pas | 20 +++++++++++++++++---
 source/dbstructures.pas |  4 +++-
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/source/dbconnection.pas b/source/dbconnection.pas
index dd90eb43..633df11d 100644
--- a/source/dbconnection.pas
+++ b/source/dbconnection.pas
@@ -2231,13 +2231,27 @@ end;
 
 procedure TPgConnection.DoBeforeConnect;
 var
-  LibraryPath: String;
+  LibraryPath,
+  msg: String;
 begin
   // Init lib before actually connecting.
   LibraryPath := ExtractFilePath(ParamStr(0)) + Parameters.LibraryFile;
   Log(lcDebug, f_('Loading library file %s ...', [LibraryPath]));
-  FLib := TPostgreSQLLib.Create(LibraryPath);
-  Log(lcDebug, FLib.DllFile + ' v' + IntToStr(FLib.PQlibVersion) + ' loaded.');
+  try
+    FLib := TPostgreSQLLib.Create(LibraryPath);
+    Log(lcDebug, FLib.DllFile + ' v' + IntToStr(FLib.PQlibVersion) + ' loaded.');
+  except
+    on E:EDbError do begin
+      msg := E.Message;
+      if E.ErrorCode = TDbLib.LIB_PROC_ERROR then begin
+        msg := msg + sLineBreak + sLineBreak +
+          f_('Installing VC redistributable might help: %s',
+            ['https://support.microsoft.com/en-us/help/3179560/update-for-visual-c-2013-and-visual-c-redistributable-package']
+            );
+      end;
+      raise EDbError.Create(msg, E.ErrorCode);
+    end;
+  end;
   inherited;
 end;
 
diff --git a/source/dbstructures.pas b/source/dbstructures.pas
index 862bc180..c5b4b6d1 100644
--- a/source/dbstructures.pas
+++ b/source/dbstructures.pas
@@ -326,6 +326,8 @@ type
 
   // DLL loading
   TDbLib = class(TObject)
+    const
+      LIB_PROC_ERROR: Cardinal = 1000;
     private
       FDllFile: String;
       FHandle: HMODULE;
@@ -7716,7 +7718,7 @@ begin
         );
       if Windows.GetLastError <> 0 then
         msg := msg + CRLF + CRLF + f_('Internal error %d: %s', [Windows.GetLastError, SysErrorMessage(Windows.GetLastError)]);
-      Raise EDbError.Create(msg);
+      Raise EDbError.Create(msg, LIB_PROC_ERROR);
     end;
   end;
 end;