insert-file-contents small gap bug

Problem reported by Zhengyi Fu (Bug#79031).
* src/fileio.c (Finsert_file_contents): Do not read more than
requested, even when the gap is so small that we use a local buffer.

(cherry picked from commit e450a7802c544b7fa14fe064c62de1f9b7098e81)

diff --git a/src/fileio.c b/src/fileio.c
index 2c8855dba911a7114eea8cd02dd231d6ac0e00f1..e33ac4afabf1003fbfad05cb695ae1fafa1fc050 100644 (file)
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -4899,8 +4899,9 @@ by calling `format-decode', which see.  */)
        else
          {
            buf = (char *) BEG_ADDR + PT_BYTE - BEG_BYTE + inserted;
-           bufsize = min (min (gap_size, total - inserted), IO_BUFSIZE);
+           bufsize = min (gap_size, IO_BUFSIZE);
          }
+       bufsize = min (bufsize, total - inserted);
 
        if (!seekable && end_offset == TYPE_MAXIMUM (off_t))
          {