sed: fix " echo /usr/lib | sed 's,\(^/\|\)[^/][^/]*,..,g' " bug

function                                             old     new   delta
process_files                                       2102    2091     -11

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/editors/sed.c b/editors/sed.c
index de18996b823211a8779a1a798efc35b6ac2161b5..8b4f60a8cd76a261e4906afbb26e3c10389c409a 100644 (file)
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -589,7 +589,7 @@ static void pipe_putc(char c)
 
 static void do_subst_w_backrefs(char *line, char *replace)
 {
-       int i,j;
+       int i, j;
 
        /* go through the replacement string */
        for (i = 0; replace[i]; i++) {
@@ -624,23 +624,24 @@ static void do_subst_w_backrefs(char *line, char *replace)
        }
 }
 
-static int do_subst_command(sed_cmd_t *sed_cmd, char **line)
+static int do_subst_command(sed_cmd_t *sed_cmd, char **line_p)
 {
-       char *oldline = *line;
+       char *line = *line_p;
        int altered = 0;
        unsigned match_count = 0;
        regex_t *current_regex;
 
+       current_regex = sed_cmd->sub_match;
        /* Handle empty regex. */
-       if (sed_cmd->sub_match == NULL) {
+       if (!current_regex) {
                current_regex = G.previous_regex_ptr;
                if (!current_regex)
                        bb_error_msg_and_die("no previous regexp");
-       } else
-               G.previous_regex_ptr = current_regex = sed_cmd->sub_match;
+       }
+       G.previous_regex_ptr = current_regex;
 
        /* Find the first match */
-       if (REG_NOMATCH == regexec(current_regex, oldline, 10, G.regmatch, 0))
+       if (REG_NOMATCH == regexec(current_regex, line, 10, G.regmatch, 0))
                return 0;
 
        /* Initialize temporary output buffer. */
@@ -657,7 +658,7 @@ static int do_subst_command(sed_cmd_t *sed_cmd, char **line)
                   The match_count check is so not to break
                   echo "hi" | busybox sed 's/^/!/g' */
                if (!G.regmatch[0].rm_so && !G.regmatch[0].rm_eo && match_count) {
-                       pipe_putc(*oldline++);
+                       pipe_putc(*line++);
                        continue;
                }
 
@@ -669,35 +670,41 @@ static int do_subst_command(sed_cmd_t *sed_cmd, char **line)
                 && (sed_cmd->which_match != match_count)
                ) {
                        for (i = 0; i < G.regmatch[0].rm_eo; i++)
-                               pipe_putc(*oldline++);
+                               pipe_putc(*line++);
                        continue;
                }
 
                /* print everything before the match */
                for (i = 0; i < G.regmatch[0].rm_so; i++)
-                       pipe_putc(oldline[i]);
+                       pipe_putc(line[i]);
 
                /* then print the substitution string */
-               do_subst_w_backrefs(oldline, sed_cmd->string);
+               do_subst_w_backrefs(line, sed_cmd->string);
 
                /* advance past the match */
-               oldline += G.regmatch[0].rm_eo;
+               line += G.regmatch[0].rm_eo;
                /* flag that something has changed */
                altered++;
 
                /* if we're not doing this globally, get out now */
                if (sed_cmd->which_match)
                        break;
-       } while (*oldline && (regexec(current_regex, oldline, 10, G.regmatch, 0) != REG_NOMATCH));
 
-       /* Copy rest of string into output pipeline */
+               if (*line == '\0')
+                       break;
+//maybe (G.regmatch[0].rm_eo ? REG_NOTBOL : 0) instead of unconditional REG_NOTBOL?
+       } while (regexec(current_regex, line, 10, G.regmatch, REG_NOTBOL) != REG_NOMATCH);
 
-       while (*oldline)
-               pipe_putc(*oldline++);
-       pipe_putc(0);
+       /* Copy rest of string into output pipeline */
+       while (1) {
+               char c = *line++;
+               pipe_putc(c);
+               if (c == '\0')
+                       break;
+       }
 
-       free(*line);
-       *line = G.pipeline.buf;
+       free(*line_p);
+       *line_p = G.pipeline.buf;
        return altered;
 }
 

diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index a9d9ada311e2e1b0f4d5d4d10feedcba4034ecbd..696d980eff26e0bd86315d0480ba1b496b4964f3 100755 (executable)
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -241,4 +241,11 @@ testing "sed 2d;2,1p (gnu compat)" \
        "third\n" "" \
        "first\nsecond\nthird\nfourth\n"
 
+# Regex means: "match / at BOL or nothing, then one or more not-slashes".
+# The bug was that second slash in /usr/lib was treated as "at BOL" too.
+testing "sed beginning (^) matches only once" \
+       "sed 's,\(^/\|\)[^/][^/]*,>\0<,g'" \
+       ">/usr</>lib<\n" "" \
+       "/usr/lib\n"
+
 exit $FAILCOUNT