sed: fix a buglet in s///NUM handling

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

2 files changed, 8 insertions, 1 deletions

diff --git a/editors/sed.c b/editors/sed.c
index e18e48ab5..e1b8352fd 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -395,7 +395,9 @@ static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
         /* process the flags */
 
         sed_cmd->which_match = 1;
+        dbg("s flags:'%s'", substr + idx + 1);
         while (substr[++idx]) {
+                dbg("s flag:'%c'", substr[idx]);
                 /* Parse match number */
                 if (isdigit(substr[idx])) {
                         if (match[0] != '^') {
@@ -403,7 +405,7 @@ static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
                                 const char *pos = substr + idx;
 /* FIXME: error check? */
                                 sed_cmd->which_match = (unsigned)strtol(substr+idx, (char**) &pos, 10);
-                                idx = pos - substr;
+                                idx = pos - substr - 1;
                         }
                         continue;
                 }
@@ -443,6 +445,7 @@ static int parse_subst_cmd(sed_cmd_t *sed_cmd, const char *substr)
                 case '}':
                         goto out;
                 default:
+                        dbg("s bad flags:'%s'", substr + idx);
                         bb_error_msg_and_die("bad option in substitution expression");
                 }
         }
diff --git a/testsuite/sed.tests b/testsuite/sed.tests
index 9494ac2de..19f2915ce 100755
--- a/testsuite/sed.tests
+++ b/testsuite/sed.tests
@@ -329,6 +329,10 @@ line with \\
 continuation
 "
 
+testing "sed s///NUM test" \
+        "sed -e 's/a/b/2; s/a/c/g'" \
+        "cb\n" "" "aa\n"
+
 # testing "description" "commands" "result" "infile" "stdin"
 
 exit $FAILCOUNT