vi: make the substitute command more like vi

Make the ':s/find/replace/g' command behave more like vi:

- the final delimiter is optional if no flag is specified;

- the cursor is moved to the first visible character of the last
  line where a substitution was made;

- a warning is displayed if no substitution was made.

function                                             old     new   delta
colon                                               3156    3212     +56
.rodata                                           105133  105142      +9
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 65/0)               Total: 65 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 17 insertions, 13 deletions

diff --git a/editors/vi.c b/editors/vi.c
index fd4526dda..4fda6aebf 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2817,10 +2817,8 @@ static void colon(char *buf)
         } else if (cmd[0] == 's') {     // substitute a pattern with a replacement pattern
                 char *F, *R, *flags;
                 size_t len_F, len_R;
-                int gflag;              // global replace flag
-#  if ENABLE_FEATURE_VI_UNDO
-                int dont_chain_first_item = ALLOW_UNDO;
-#  endif
+                int gflag = 0;          // global replace flag
+                int subs = 0;   // number of substitutions
 
                 // F points to the "find" pattern
                 // R points to the "replace" pattern
@@ -2833,11 +2831,11 @@ static void colon(char *buf)
                 len_F = R - F;
                 *R++ = '\0';    // terminate "find"
                 flags = strchr(R, c);
-                if (!flags)
-                        goto colon_s_fail;
-                len_R = flags - R;
-                *flags++ = '\0';        // terminate "replace"
-                gflag = *flags;
+                if (flags) {
+                        *flags++ = '\0';        // terminate "replace"
+                        gflag = *flags;
+                }
+                len_R = strlen(R);
 
                 q = begin_line(q);
                 if (b < 0) {    // maybe :s/foo/bar/
@@ -2856,14 +2854,15 @@ static void colon(char *buf)
                                 uintptr_t bias;
                                 // we found the "find" pattern - delete it
                                 // For undo support, the first item should not be chained
-                                text_hole_delete(found, found + len_F - 1, dont_chain_first_item);
-#  if ENABLE_FEATURE_VI_UNDO
-                                dont_chain_first_item = ALLOW_UNDO_CHAIN;
-#  endif
+                                text_hole_delete(found, found + len_F - 1,
+                                                        subs ? ALLOW_UNDO_CHAIN: ALLOW_UNDO);
+                                // can't do this above, no undo => no third argument
+                                subs++;
                                 // insert the "replace" patern
                                 bias = string_insert(found, R, ALLOW_UNDO_CHAIN);
                                 found += bias;
                                 ls += bias;
+                                dot = ls;
                                 //q += bias; - recalculated anyway
                                 // check for "global"  :s/foo/bar/g
                                 if (gflag == 'g') {
@@ -2875,6 +2874,11 @@ static void colon(char *buf)
                         }
                         q = next_line(ls);
                 }
+                if (subs == 0) {
+                        status_line_bold("No match");
+                } else {
+                        dot_skip_over_ws();
+                }
 # endif /* FEATURE_VI_SEARCH */
         } else if (strncmp(cmd, "version", i) == 0) {  // show software version
                 status_line(BB_VER);