less: correctly wrap lines with tabs

This commit is contained in:
Denis Vlasenko 2008-10-26 16:30:09 +00:00
parent c94fa5651a
commit e1ef89abad

View File

@ -65,7 +65,7 @@ struct globals {
int kbd_fd; /* fd to get input from */
int less_gets_pos;
/* last position in last line, taking into account tabs */
size_t linepos;
size_t last_line_pos;
unsigned max_fline;
unsigned max_lineno; /* this one tracks linewrap */
unsigned max_displayed_line;
@ -102,7 +102,7 @@ struct globals {
#define cur_fline (G.cur_fline )
#define kbd_fd (G.kbd_fd )
#define less_gets_pos (G.less_gets_pos )
#define linepos (G.linepos )
#define last_line_pos (G.last_line_pos )
#define max_fline (G.max_fline )
#define max_lineno (G.max_lineno )
#define max_displayed_line (G.max_displayed_line)
@ -197,7 +197,7 @@ static void less_exit(int code)
static void re_wrap(void)
{
int w = width;
int rem;
int new_line_pos;
int src_idx;
int dst_idx;
int new_cur_fline = 0;
@ -216,14 +216,16 @@ static void re_wrap(void)
s = old_flines[0];
lineno = LINENO(s);
d = linebuf;
rem = w;
new_line_pos = 0;
while (1) {
*d = *s;
if (*d != '\0') {
new_line_pos++;
if (*d == '\t') /* tab */
new_line_pos += 7;
s++;
d++;
rem--;
if (rem == 0) {
if (new_line_pos >= w) {
int sz;
/* new line is full, create next one */
*d = '\0';
@ -235,28 +237,26 @@ static void re_wrap(void)
new_flines = xrealloc_vector(new_flines, 8, dst_idx);
new_flines[dst_idx] = d;
dst_idx++;
if (rem) {
/* did we come here thru "goto next_new"? */
if (new_line_pos < w) {
/* if we came here thru "goto next_new" */
if (src_idx > max_fline)
break;
lineno = LINENO(s);
}
d = linebuf;
rem = w;
new_line_pos = 0;
}
continue;
}
/* *d == NUL: old line ended, go to next old one */
free(MEMPTR(old_flines[src_idx]));
/* btw, convert cur_fline... */
if (cur_fline == src_idx) {
if (cur_fline == src_idx)
new_cur_fline = dst_idx;
}
src_idx++;
/* no more lines? finish last new line (and exit the loop) */
if (src_idx > max_fline) {
if (src_idx > max_fline)
goto next_new;
}
s = old_flines[src_idx];
if (lineno != LINENO(s)) {
/* this is not a continuation line!
@ -269,7 +269,7 @@ static void re_wrap(void)
flines = (const char **)new_flines;
max_fline = dst_idx - 1;
linepos = 0; // XXX
last_line_pos = new_line_pos;
cur_fline = new_cur_fline;
/* max_lineno is screen-size independent */
pattern_valid = 0;
@ -301,7 +301,7 @@ static void fill_match_lines(unsigned pos);
* on line wrap, only on "real" new lines.
* readbuf[0..readeof-1] - small preliminary buffer.
* readbuf[readpos] - next character to add to current line.
* linepos - screen line position of next char to be read
* last_line_pos - screen line position of next char to be read
* (takes into account tabs and backspaces)
* eof_error - < 0 error, == 0 EOF, > 0 not EOF/error
*/
@ -329,9 +329,9 @@ static void read_lines(void)
strcpy(p, cp);
p += strlen(current_line);
free(MEMPTR(flines[max_fline]));
/* linepos is still valid from previous read_lines() */
/* last_line_pos is still valid from previous read_lines() */
} else {
linepos = 0;
last_line_pos = 0;
}
while (1) { /* read lines until we reach cur_fline or wanted_match */
@ -353,28 +353,28 @@ static void read_lines(void)
/* backspace? [needed for manpages] */
/* <tab><bs> is (a) insane and */
/* (b) harder to do correctly, so we refuse to do it */
if (c == '\x8' && linepos && p[-1] != '\t') {
if (c == '\x8' && last_line_pos && p[-1] != '\t') {
readpos++; /* eat it */
linepos--;
last_line_pos--;
/* was buggy (p could end up <= current_line)... */
*--p = '\0';
continue;
}
{
size_t new_linepos = linepos + 1;
size_t new_last_line_pos = last_line_pos + 1;
if (c == '\t') {
new_linepos += 7;
new_linepos &= (~7);
new_last_line_pos += 7;
new_last_line_pos &= (~7);
}
if ((int)new_linepos >= w)
if ((int)new_last_line_pos >= w)
break;
linepos = new_linepos;
last_line_pos = new_last_line_pos;
}
/* ok, we will eat this char */
readpos++;
if (c == '\n') {
terminated = 1;
linepos = 0;
last_line_pos = 0;
break;
}
/* NUL is substituted by '\n'! */
@ -449,7 +449,7 @@ static void read_lines(void)
max_fline++;
current_line = ((char*)xmalloc(w + 4)) + 4;
p = current_line;
linepos = 0;
last_line_pos = 0;
} /* end of "read lines until we reach cur_fline" loop */
fill_match_lines(old_max_fline);
#if ENABLE_FEATURE_LESS_REGEXP
@ -778,7 +778,7 @@ static void open_file_and_read_lines(void)
}
readpos = 0;
readeof = 0;
linepos = 0;
last_line_pos = 0;
terminated = 1;
read_lines();
}