COMP: gcc-12 buffer check bypasses xsputn (#2481, #2496)

- add overflow() method to the SHA1 streambuf. Previously could rely
  on xsputn for adding to sha1 content, but streams now check pptr()
  first to test for the buffering range and thus overflow() is needed.

src/OpenFOAM/db/IOstreams/hashes/OSHA1stream.H

@@ -32,8 +32,8 @@ Description
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef OSHA1stream_H
-#define OSHA1stream_H
+#ifndef Foam_OSHA1stream_H
+#define Foam_OSHA1stream_H
 
 #include "OSstream.H"
 #include "SHA1.H"
@@ -63,10 +63,17 @@ class osha1stream
 
     protected:
 
+        //- Handle overflow
+        virtual int overflow(int c = EOF)
+        {
+            if (c != EOF) sha1_.append(c);
+            return c;
+        }
+
         //- Put sequence of characters
         virtual std::streamsize xsputn(const char* s, std::streamsize n)
         {
-            sha1_.append(s, n);
+            if (n) sha1_.append(s, n);
             return n;
         }
 

src/OpenFOAM/primitives/hashes/SHA1/SHA1.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011-2016 OpenFOAM Foundation
-    Copyright (C) 2019 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -42,8 +42,8 @@ SourceFiles
 
 \*---------------------------------------------------------------------------*/
 
-#ifndef SHA1_H
-#define SHA1_H
+#ifndef Foam_SHA1_H
+#define Foam_SHA1_H
 
 #include <string>
 #include <cstdint>
@@ -113,6 +113,9 @@ public:
         //- Reset the hashed data before appending more
         void clear() noexcept;
 
+        //- Append single character
+        inline void append(char c);
+
         //- Append data for processing
         inline SHA1& append(const char* str);
 

src/OpenFOAM/primitives/hashes/SHA1/SHA1I.H

@@ -6,7 +6,7 @@
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
     Copyright (C) 2011 OpenFOAM Foundation
-    Copyright (C) 2019-2021 OpenCFD Ltd.
+    Copyright (C) 2019-2022 OpenCFD Ltd.
 -------------------------------------------------------------------------------
 License
     This file is part of OpenFOAM.
@@ -52,6 +52,12 @@ inline Foam::SHA1::SHA1(const std::string& str)
 
 // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
 
+inline void Foam::SHA1::append(char c)
+{
+    processBytes(&c, 1);
+}
+
+
 inline Foam::SHA1& Foam::SHA1::append(const char* data, size_t len)
 {
     processBytes(data, len);