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author | Emmanuele Bassi <ebassi@gnome.org> | 2018-04-10 14:51:27 +0100 |
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committer | Emmanuele Bassi <ebassi@gnome.org> | 2018-04-10 14:54:45 +0100 |
commit | 14c8a603e3b307d2f247764a828d390980854b0d (patch) | |
tree | 10d8f95e6ce30d0b1313c4ca23b88c4fa1699555 /modules | |
parent | adc0159bdb733eaa870b8e12a4a14547a8d96407 (diff) | |
download | gtk+-14c8a603e3b307d2f247764a828d390980854b0d.tar.gz |
Terminate strncpy() buffers correctly
When using strncpy() with a buffer we need to account for the
terminating NUL character. GCC 8 started warning when using PPD_MAX_NAME
as the buffer length for strncpy() because the buffer we're copying into
has the same length — which means that the terminating NUL may be
skipped if the source string has a length of PPD_MAX_NAME.
The appropriate way to handle the case where we're copying a source with
a length bigger than of PPD_MAX_NAME is, as reported in the strncpy()
documentation, to copy `PPD_MAX_NAME - 1` bytes, and explicitly NUL
terminate the destination buffer. This has the additional benefit of
avoiding the compiler warning.
Diffstat (limited to 'modules')
-rw-r--r-- | modules/printbackends/gtkprintbackendcups.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/modules/printbackends/gtkprintbackendcups.c b/modules/printbackends/gtkprintbackendcups.c index 09e18b170e..52614069d2 100644 --- a/modules/printbackends/gtkprintbackendcups.c +++ b/modules/printbackends/gtkprintbackendcups.c @@ -5590,7 +5590,10 @@ cups_printer_get_options (GtkPrinter *printer, ppd_name = gtk_paper_size_get_ppd_name (paper_size); if (ppd_name) - strncpy (ppd_option->defchoice, ppd_name, PPD_MAX_NAME); + { + strncpy (ppd_option->defchoice, ppd_name, PPD_MAX_NAME - 1); + ppd_option->defchoice[PPD_MAX_NAME - 1] = '\0'; + } else { gchar *custom_name; @@ -5609,7 +5612,8 @@ cups_printer_get_options (GtkPrinter *printer, * 230.4x142.9" */ custom_name = g_strdup_printf (_("Custom %s×%s"), width, height); - strncpy (ppd_option->defchoice, custom_name, PPD_MAX_NAME); + strncpy (ppd_option->defchoice, custom_name, PPD_MAX_NAME - 1); + ppd_option->defchoice[PPD_MAX_NAME - 1] = '\0'; g_free (custom_name); } } |