From 8d4e1bf0c2fd6635c735b42aebc3fe0645f270bf Mon Sep 17 00:00:00 2001
From: florian <florian@3ad0048d-3df7-0310-abae-a5850022a9f2>
Date: Sun, 25 Apr 2021 19:49:26 +0000
Subject:   * decrease macro nesting counter early when expanding empty macro  
   to avoid errors about too depth macro nesting, resolves #38802

git-svn-id: https://svn.freepascal.org/svn/fpc/trunk@49265 3ad0048d-3df7-0310-abae-a5850022a9f2
---
 compiler/scanner.pas | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

(limited to 'compiler')

diff --git a/compiler/scanner.pas b/compiler/scanner.pas
index b33f7a73c5..9632471f24 100644
--- a/compiler/scanner.pas
+++ b/compiler/scanner.pas
@@ -4883,12 +4883,21 @@ type
                        inc(yylexcount);
                        substitutemacro(pattern,mac.buftext,mac.buflen,
                          mac.fileinfo.line,mac.fileinfo.fileindex);
-                     { handle empty macros }
+                       { handle empty macros }
                        if c=#0 then
-                         reload;
-                       readtoken(false);
-                       { that's all folks }
-                       dec(yylexcount);
+                         begin
+                           reload;
+                           { avoid macro nesting error in case of
+                             a sequence of empty macros, see #38802 }
+                           dec(yylexcount);
+                           readtoken(false);
+                         end
+                       else
+                         begin
+                           readtoken(false);
+                           { that's all folks }
+                           dec(yylexcount);
+                         end;
                        exit;
                      end
                     else
-- 
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