nano

commit 455a918071c659458f1f34b7a219dcbe0a9c2aeb
parent 296152ec67e10c96e29254909876f86b238e4927
Author: Benno Schulenberg <bensberg@justemail.net>
Date:   Sat, 18 Apr 2015 20:07:31 +0000

Making sure an invalid starting byte of a multibyte sequence is properly
terminated, to prevent the displaying of ghost characters.


git-svn-id: svn://svn.savannah.gnu.org/nano/trunk/nano@5206 35c25a1d-7b9e-4130-9fde-d3aeb78583b8

Diffstat:
M
ChangeLog
 | 
8
++++++++
M
src/winio.c
 | 
14
++++++++------

2 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/ChangeLog b/ChangeLog
@@ -1,6 +1,14 @@
 2015-04-18  Benno Schulenberg  <bensberg@justemail.net>
 	* src/global.c, src/nano.c, doc/man/nanorc.5, doc/texinfo/nano.texi:
 	Make the descriptions of the multibuffer feature more accurate.
+	* src/winio.c (display_string): Make sure an invalid starting byte
+	of a multibyte sequence is properly terminated, so that it doesn't
+	pick up lingering bytes of any previous content.  This prevents the
+	displaying of ghosts -- characters that aren't really there -- when a
+	file contains valid ánd invalid UTF-8 sequences.  For an example see:
+	https://lists.gnu.org/archive/html/nano-devel/2015-04/msg00052.html.
+	Also make two comments more accurate: an invalid multibyte sequence
+	will never be categorized as a control character or anything else.
 
 2015-04-18  Mark Oteiza  <mvoteiza@udel.edu>
 	* doc/syntax/{python,ruby,sh,tex}.nanorc: Add a linter definition.
diff --git a/src/winio.c b/src/winio.c
@@ -2004,9 +2004,7 @@ char *display_string(const char *buf, size_t start_col, size_t len, bool
 		converted[index++] = ' ';
 		start_col++;
 	    }
-	/* If buf contains a control character, interpret it.  If buf
-	 * contains an invalid multibyte control character, display it
-	 * as such. */
+	/* If buf contains a control character, interpret it. */
 	} else if (is_cntrl_mbchar(buf_mb)) {
 	    char *ctrl_buf_mb = charalloc(mb_cur_max());
 	    int ctrl_buf_mb_len, i;
@@ -2036,13 +2034,17 @@ char *display_string(const char *buf, size_t start_col, size_t len, bool
 #endif
 		converted[index++] = ' ';
 	    start_col++;
-	/* If buf contains a non-control character, interpret it.  If
-	 * buf contains an invalid multibyte non-control character,
-	 * display it as such. */
+	/* If buf contains a non-control character, interpret it.  If buf
+	 * contains an invalid multibyte sequence, display it as such. */
 	} else {
 	    char *nctrl_buf_mb = charalloc(mb_cur_max());
 	    int nctrl_buf_mb_len, i;
 
+	    /* Make sure an invalid sequence-starter byte is properly
+	     * terminated, so that it doesn't pick up lingering bytes
+	     * of any previous content. */
+	    null_at(&buf_mb, buf_mb_len);
+
 	    nctrl_buf_mb = mbrep(buf_mb, nctrl_buf_mb,
 		&nctrl_buf_mb_len);