col: make flush_line() a little bit robust

The code is horrible. The core of the problem are signed integers
and no check for the limits.

This patch fixes c->c_column = cur_col; where c_column is "short"
and "cur_col" is int. Let's use "int" for all the variables. It's
really not perfect as for bigger lines it can segfault again...

The patch also removes some unnecessary static variables.

Addresses: https://github.com/karelzak/util-linux/issues/749
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/text-utils/col.c b/text-utils/col.c
index 3d9e15d26573445e937f004a93058e923ab3e27d..c6b2bdf568e50fa100032e0649adba869d6a9df9 100644 (file)
--- a/text-utils/col.c
+++ b/text-utils/col.c
@@ -88,7 +88,7 @@ typedef char CSET;
 typedef struct char_str {
 #define        CS_NORMAL       1
 #define        CS_ALTERNATE    2
-       short           c_column;       /* column character is in */
+       int             c_column;       /* column character is in */
        CSET            c_set;          /* character set (currently only 2) */
        wchar_t         c_char;         /* character in question */
        int             c_width;        /* character width */
@@ -243,7 +243,7 @@ int main(int argc, char **argv)
                errno = 0;
                if ((ch = getwchar()) == WEOF) {
                        if (errno == EILSEQ) {
-                               warn(NULL);
+                               warn(_("failed on line %d"), max_line);
                                ret = EXIT_FAILURE;
                        }
                        break;
@@ -476,8 +476,9 @@ void flush_line(LINE *l)
        nchars = l->l_line_len;
 
        if (l->l_needs_sort) {
-               static CHAR *sorted;
-               static int count_size, *count, i, save, sorted_size, tot;
+               static CHAR *sorted = NULL;
+               static int count_size = 0, *count = NULL, sorted_size = 0;
+               int i, tot;
 
                /*
                 * Do an O(n) sort on l->l_line by column being careful to
@@ -494,7 +495,7 @@ void flush_line(LINE *l)
                            (unsigned)sizeof(int) * count_size);
                }
                memset(count, 0, sizeof(int) * l->l_max_col + 1);
-               for (i = nchars, c = l->l_line; --i >= 0; c++)
+               for (i = nchars, c = l->l_line; c && --i >= 0; c++)
                        count[c->c_column]++;
 
                /*
@@ -502,7 +503,7 @@ void flush_line(LINE *l)
                 * indices into new line.
                 */
                for (tot = 0, i = 0; i <= l->l_max_col; i++) {
-                       save = count[i];
+                       int save = count[i];
                        count[i] = tot;
                        tot += save;
                }