[PATCH] rev: fix some issues

[Grisha Levit]

examples/loadables/rev.c
- include config.h to fix build (e.g., with unlocked-io)
- getlen: avoid reading one byte before start of line
- reverse_line: make sure BUF can fit the separator, if needed
- rev_internal: do not require an argument for the -0 option
- rev_internal: make sure to close any FD we opened, even if FD==0
---
 examples/loadables/rev.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/examples/loadables/rev.c b/examples/loadables/rev.c
index b8d7d4d8..e15ca445 100644
--- a/examples/loadables/rev.c
+++ b/examples/loadables/rev.c
@@ -43,6 +43,8 @@
 
 /* Headers */
 
+#include "config.h"
+
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
@@ -86,6 +88,7 @@ getlen(char *last_trlg_byte, int num_bytes_left)
 
   if ((*p-- & mask[1]) != mask[0])
     goto not_utf_8;
+  num_bytes_left--;
   n = 2;
   for (i = num_bytes_left >= 3 ? 3 : num_bytes_left; i > 0; i--, p--, n++)
   {                                /* 3 more bytes max */
@@ -119,9 +122,9 @@ reverse_line(SHELL_VAR *v, arrayind_t *ind, char *line, 
size_t len,
      * with NULL value and putting an allocated buffer in it.
      */
     bind_array_element (v, (*ind)++, (char *)NULL, 0);
-    buf = xmalloc(len + 1);        /* +1 for NUL */
+    buf = xmalloc(len + outputsep + 1);        /* +1 for NUL */
     (((ARRAY *)v->value)->lastref)->value = buf;
-    buf[len] = '\0';
+    buf[len + outputsep] = '\0';
   }                                /* if (v) */
 #endif
 
@@ -177,7 +180,7 @@ rev_internal(WORD_LIST *list)
   ind = 0;
 
   reset_internal_getopt();
-  while ((opt = internal_getopt(list, "0:a:h")) != -1)
+  while ((opt = internal_getopt(list, "0a:h")) != -1)
     switch (opt)
     {
       case '0':
@@ -221,15 +224,17 @@ rev_internal(WORD_LIST *list)
 /* for each file */
 
     if (l == 0)
-      fd = 0;
+      fd = -1;
     else
-      SYSCALL(fd, open(l->word->word, O_RDONLY));
-    if (fd == -1)
-    {
-      file_error(l->word->word);
-      rval = EXECUTION_FAILURE;
-      goto next_file;
-    }
+      {
+       SYSCALL(fd, open(l->word->word, O_RDONLY));
+       if (fd == -1)
+         {
+           file_error(l->word->word);
+           rval = EXECUTION_FAILURE;
+           goto next_file;
+         }
+      }
 
 #ifndef __CYGWIN__
     unbuffered_read = (lseek(fd, 0L, SEEK_CUR) < 0) && (errno == ESPIPE);
@@ -250,7 +255,7 @@ rev_internal(WORD_LIST *list)
       }
       reverse_line(v, &ind, line, n, outputsep, sep);
     }                              /* while ((n = zgetline(...) !=-1) */
-    if (fd != 0)
+    if (fd != -1)
       close(fd);
 
   next_file:
-- 
2.54.0