insert-file-contents errno confusion

* src/fileio.c (read_non_regular): Return negation of
errno on failure, instead of -1.
(Finsert_file_contents): Signal with correct errno when a read fails.

(cherry picked from commit 490311f86a97fd8d6633e28143a26e7618f15e79)

diff --git a/src/fileio.c b/src/fileio.c
index 748e8aadc0c46556ab25963a80681bc6b20b4fac..7aa2113454b9384d33d69175aeb3e3feb0795653 100644 (file)
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -3924,7 +3924,7 @@ read_non_regular (Lisp_Object state)
                     ((char *) BEG_ADDR + PT_BYTE - BEG_BYTE
                      + data->s.inserted),
                     data->s.trytry);
-  return make_int (nbytes);
+  return make_int (nbytes < 0 ? -errno : nbytes);
 }
 
 
@@ -4094,8 +4094,8 @@ by calling `format-decode', which see.  */)
   bool replace_handled = false;
   bool set_coding_system = false;
   Lisp_Object coding_system;
-  /* Negative if read error, 0 if OK so far, positive if quit.  */
-  ptrdiff_t read_quit = 0;
+  /* errno if read error, 0 if OK so far, negative if quit.  */
+  int read_quit = 0;
   /* If the undo log only contains the insertion, there's no point
      keeping it.  It's typically when we first fill a file-buffer.  */
   bool empty_undo_list_p
@@ -4843,7 +4843,7 @@ by calling `format-decode', which see.  */)
 
            if (NILP (nbytes))
              {
-               read_quit = 1;
+               read_quit = -1;
                break;
              }
 
@@ -4857,14 +4857,18 @@ by calling `format-decode', which see.  */)
          /* Allow quitting out of the actual I/O.  We don't make text
             part of the buffer until all the reading is done, so a
             C-g here doesn't do any harm.  */
-         this = emacs_fd_read (fd,
-                               ((char *) BEG_ADDR + PT_BYTE - BEG_BYTE
-                                + inserted),
-                               trytry);
+         {
+           this = emacs_fd_read (fd,
+                                 ((char *) BEG_ADDR + PT_BYTE - BEG_BYTE
+                                  + inserted),
+                                 trytry);
+           if (this < 0)
+             this = -errno;
+         }
 
        if (this <= 0)
          {
-           read_quit = this;
+           read_quit = -this;
            break;
          }
 
@@ -4889,8 +4893,8 @@ by calling `format-decode', which see.  */)
   emacs_fd_close (fd);
   clear_unwind_protect (fd_index);
 
-  if (read_quit < 0)
-    report_file_error ("Read error", orig_filename);
+  if (0 < read_quit)
+    report_file_errno ("Read error", orig_filename, read_quit);
 
  notfound: