Merge branch 'memstream-peek'

Return 1 from LastRead() after successful wxMemoryInputStream::Peek()
call.

See #23758.

interface/wx/stream.h

@@ -610,12 +610,18 @@ public:
     int GetC();
 
     /**
-        Returns the last number of bytes read.
+        Returns the last number of bytes read by the last input operation.
+
+        Such operations include Read(), GetC() and Peek().
     */
     virtual size_t LastRead() const;
 
     /**
         Returns the first character in the input queue without removing it.
+
+        If Peek() failed, e.g. because there is nothing more to read in the
+        stream, LastRead() will return 0 after calling it, otherwise it will
+        return 1.
     */
     virtual char Peek();
 

src/common/mstream.cpp

@@ -112,10 +112,12 @@ char wxMemoryInputStream::Peek()
     if ( pos == m_length )
     {
         m_lasterror = wxSTREAM_READ_ERROR;
+        m_lastcount = 0;
 
         return 0;
     }
 
+    m_lastcount = 1;
     return buf[pos];
 }
 

tests/streams/bstream.h

@@ -253,9 +253,17 @@ protected:
         while (stream_in.IsOk())
         {
             char peekChar = stream_in.Peek();
+            size_t peekLastRead = stream_in.LastRead();
+
             char getChar = stream_in.GetC();
+
+            // Peek and GetC should retrieve the same 0 or 1 characters.
+            CPPUNIT_ASSERT_EQUAL(peekLastRead, stream_in.LastRead());
+
             if (stream_in.LastRead() == 1)
+            {
                 CPPUNIT_ASSERT_EQUAL(getChar, peekChar);
+            }
         }
     }