commit bcd39b7b9bd3a7f8a6a34410169794a6264a6fed
Author: Victor Stinner <vstinner@redhat.com>
Date:   Wed Nov 7 00:45:13 2018 +0100

    bpo-25083: Python can sometimes create incorrect .pyc files
    
    Python 2 never checked for I/O error when reading .py files and
    thus could mistake an I/O error for EOF and create incorrect .pyc
    files. This adds an check for this and aborts on an error.
    
    Patch by tzickel, commit f64c813de84011a84ca21d75a294861a9cc2dfdc.

    Resolves: rhbz#1629982

diff --git a/Include/errcode.h b/Include/errcode.h
index becec80..5c5a0f7 100644
--- a/Include/errcode.h
+++ b/Include/errcode.h
@@ -29,6 +29,7 @@ extern "C" {
 #define E_EOFS		23	/* EOF in triple-quoted string */
 #define E_EOLS		24	/* EOL in single-quoted string */
 #define E_LINECONT	25	/* Unexpected characters after a line continuation */
+#define E_IO    	26	/* I/O error */
 
 #ifdef __cplusplus
 }
diff --git a/Parser/tokenizer.c b/Parser/tokenizer.c
index ee6313b..0217f2b 100644
--- a/Parser/tokenizer.c
+++ b/Parser/tokenizer.c
@@ -1644,6 +1644,11 @@ int
 PyTokenizer_Get(struct tok_state *tok, char **p_start, char **p_end)
 {
     int result = tok_get(tok, p_start, p_end);
+    if (tok->fp && ferror(tok->fp)) {
+        clearerr(tok->fp);
+        result = ERRORTOKEN;
+        tok->done = E_IO;
+    }
     if (tok->decoding_erred) {
         result = ERRORTOKEN;
         tok->done = E_DECODE;
diff --git a/Python/pythonrun.c b/Python/pythonrun.c
index 0b73f3a..9f06236 100644
--- a/Python/pythonrun.c
+++ b/Python/pythonrun.c
@@ -1643,6 +1643,9 @@ err_input(perrdetail *err)
         Py_XDECREF(tb);
         break;
     }
+    case E_IO:
+        msg = "I/O error while reading";
+        break;
     case E_LINECONT:
         msg = "unexpected character after line continuation character";
         break;