Stop using InputSource::unreadCh

1 files changed, 6 insertions, 1 deletions

diff --git a/include/qpdf/InputSource.hh b/include/qpdf/InputSource.hh
index 8850828d..22e3abcd 100644
--- a/include/qpdf/InputSource.hh
+++ b/include/qpdf/InputSource.hh
@@ -85,9 +85,14 @@ class QPDF_DLL_CLASS InputSource
     virtual size_t read(char* buffer, size_t length) = 0;
 
     // Note: you can only unread the character you just read. The
-    // specific character is ignored by some implementations.
+    // specific character is ignored by some implementations. unreadCh
+    // will be removed from the API in qpdf 11.
     virtual void unreadCh(char ch) = 0;
 
+    // ABI: delete unreadCh, and direct people to seek backward by 1
+    // character instead.
+    // virtual void unreadCh(char ch) final = delete;
+
   protected:
     qpdf_offset_t last_offset;