[PATCH 2/2] iconv_prog: Track if invalid sequences were seen.

[Benjamin Herr <ben at 0x539 dot de>]

As far as I can tell, Posix requires that "The presence or absence of -c
shall not affect the exit status of iconv." iconv_prog needs to be more
vigilant to not clobber the variable tracking whether it has skipped an
invalid input sequence.

In addition, it seems reasonable to treat an incomplete input sequence
at the end of the input the same way as an invalid input sequence
elsewhere if -c is passed.
---
2015-08-09  Benjamin Herr  <ben@0x539.de>

	* iconv/iconv_prog.c: Track more diligently whether an invalid input
	sequence has been encountered.


 iconv/iconv_prog.c | 68 +++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 47 insertions(+), 21 deletions(-)

diff --git a/iconv/iconv_prog.c b/iconv/iconv_prog.c
index a935402..809e18f 100644
--- a/iconv/iconv_prog.c
+++ b/iconv/iconv_prog.c
@@ -540,36 +540,39 @@ process_part (iconv_t cd, char **addr, size_t *len, size_t offset,
   char *outptr;
   size_t outlen;
   size_t n;
-  int ret = 0;
+  int invalid_sequence_seen = 0;
 
-  while (*len > 0)
+  for (;;)
     {
       outptr = outbuf;
       outlen = BUF_SIZE;
       n = iconv (cd, addr, len, &outptr, &outlen);
 
-      if (n == (size_t) -1 && omit_invalid && errno == EILSEQ)
-	{
-	  ret = 1;
-	  if (*len == 0)
-	    n = 0;
-	  else
-	    errno = E2BIG;
-	}
-
       if (outptr != outbuf)
 	{
-	  ret = write_output (outbuf, outptr, output, output_file);
+	  int ret = write_output (outbuf, outptr, output, output_file);
 	  if (ret != 0)
-	    break;
+	    return ret;
 	}
 
+      /* Done with the input buffer.  */
+      if (n != (size_t) -1)
+	break;
+
       /* Incomplete multibyte characters might be completed by the next
          chunk, so do not treat them as an error here. */
-      if (n != (size_t) -1 || errno == EINVAL)
+      if (errno == EINVAL)
+	break;
+
+      if (omit_invalid && errno == EILSEQ)
 	{
-	  ret = 0;
-	  break;
+	  /* Remember that we saw an invalid character for the sake of our
+	     exit status, but otherwise carry on.  */
+	  invalid_sequence_seen = 1;
+	  if (*len == 0)
+	    break;
+	  else
+	    errno = E2BIG;
 	}
 
       if (errno != E2BIG)
@@ -581,7 +584,7 @@ process_part (iconv_t cd, char **addr, size_t *len, size_t offset,
 	}
     }
 
-  return ret;
+  return invalid_sequence_seen;
 }
 
 static int
@@ -589,6 +592,7 @@ process_block (iconv_t cd, char *addr, size_t len, FILE **output,
 	       const char *output_file)
 {
   char *start = addr;
+  int invalid_sequence_seen = 0;
 
   /* Process everything in one go.  */
   int ret = process_part (cd, &addr, &len, 0, output, output_file);
@@ -600,12 +604,24 @@ process_block (iconv_t cd, char *addr, size_t len, FILE **output,
      sequence at the end.  */
   if (len > 0)
     {
+      /* Incomplete multibyte sequences at the end of the input are not any
+         more invalid than spurious bytes anywhere else.  */
+      if (omit_invalid)
+	return 1;
+
       errno = EINVAL;
       report_iconv_error (addr - start);
       return -1;
     }
 
-  return flush_state (cd, output, output_file, addr - start);
+  if (ret > 0)
+    invalid_sequence_seen = ret;
+
+  ret = flush_state (cd, output, output_file, addr - start);
+  if (ret != 0)
+    return ret;
+  else
+    return invalid_sequence_seen;
 }
 
 
@@ -616,11 +632,12 @@ process_fd (iconv_t cd, int fd, FILE **output, const char *output_file)
   size_t len = 0;
   size_t offset = 0;
   ssize_t n;
+  int ret;
+  int invalid_sequence_seen = 0;
 
   /* Read into the buffer past unconsumed bytes from the last iteration.  */
   while ((n = read (fd, inbuf + len, BUF_SIZE - len)) > 0)
     {
-      int ret;
       char *inptr;
 
       len += n;
@@ -628,8 +645,13 @@ process_fd (iconv_t cd, int fd, FILE **output, const char *output_file)
       inptr = inbuf;
       /* Process what we have read.  */
       ret = process_part (cd, &inptr, &len, offset, output, output_file);
-      if (ret != 0)
+      if (ret < 0)
 	return ret;
+
+      /* Remember this for the sake of our exit status, but carry on.  */
+      if (ret > 0)
+	invalid_sequence_seen = ret;
+
       /* Keep track of overall position in the input for error reporting.  */
       offset = saturating_add (offset, inptr - inbuf);
 
@@ -653,7 +675,11 @@ process_fd (iconv_t cd, int fd, FILE **output, const char *output_file)
       return -1;
     }
 
-  return flush_state (cd, output, output_file, offset);
+  ret = flush_state (cd, output, output_file, offset);
+  if (ret != 0)
+    return ret;
+  else
+    return invalid_sequence_seen;
 }
 
 
-- 
2.5.0