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.

1 files changed, 15 insertions, 11 deletions

diff --git a/src/fileio.c b/src/fileio.c
index 748e8aadc0c..7aa2113454b 100644
--- 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: