2 files changed, 14 insertions, 11 deletions

diff --git a/editors/vi.c b/editors/vi.c
index 5bc180b5d..814a63a7b 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -2850,7 +2850,7 @@ static void colon(char *buf)
         not_implemented(p);
 #else
         char c, *q, *r;
-        char *fn, cmd[MAX_INPUT_LEN], *cmdend, *args;
+        char *fn, cmd[MAX_INPUT_LEN], *args;
         char *exp = NULL;
         char *useforce;
         int cmdlen;
@@ -2890,15 +2890,14 @@ static void colon(char *buf)
                 goto ret;
 
         // get the COMMAND into cmd[]
-        strcpy(cmd, buf);
-        cmdend = skip_non_whitespace(cmd);
-        // get any ARGuments
-        args = skip_whitespace(cmdend);
-//NB: arguments can be accessed in buf[] as well, there is no need to copy them into cmd[]?
-        *cmdend = '\0';
+        args = skip_non_whitespace(buf);
+        safe_strncpy(cmd, buf, (args - buf) + 1);
+//NB: in "s/find/repl" and "!CMD" cases, we copy unnecessary data into buf[]
         useforce = last_char_is(cmd, '!');
         if (useforce && useforce > cmd)
                 *useforce = '\0';   // "CMD!" -> "CMD" (unless single "!")
+        // find ARGuments
+        args = skip_whitespace(args);
 
         // assume the command will want a range, certain commands
         // (read, substitute) need to adjust these assumptions
@@ -3151,7 +3150,9 @@ static void colon(char *buf)
                         editing = 0;
                 }
 # if ENABLE_FEATURE_VI_SET
-        } else if (strncmp(cmd, "set", cmdlen) == 0) {  // set or clear features
+        } else if (strncmp(cmd, "set", cmdlen) == 0     // set or clear features
+                IF_FEATURE_VI_SEARCH(&& cmdlen > 1)     // (do not confuse with "s /find/repl/")
+        ) {
 #  if ENABLE_FEATURE_VI_SETOPTS
                 char *argp, *argn, oldch;
 #  endif
@@ -3210,12 +3211,12 @@ static void colon(char *buf)
                 int undo = 0;
 #   endif
 #  endif
-
+                buf = skip_whitespace(buf + 1); // spaces allowed: "s  /find/repl/"
                 // F points to the "find" pattern
                 // R points to the "replace" pattern
                 // replace the cmd line delimiters "/" with NULs
-                c = buf[1];     // what is the delimiter
-                F = buf + 2;    // start of "find"
+                c = buf[0];     // what is the delimiter
+                F = buf + 1;    // start of "find"
                 R = strchr_backslash(F, c);     // middle delimiter
                 if (!R)
                         goto colon_s_fail;
diff --git a/include/libbb.h b/include/libbb.h
index 6ce01ea94..baf0f29e5 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -939,6 +939,8 @@ int parse_pasv_epsv(char *buf) FAST_FUNC;
 /* 0 if argv[0] is NULL: */
 unsigned string_array_len(char **argv) FAST_FUNC;
 void overlapping_strcpy(char *dst, const char *src) FAST_FUNC;
+/* Like strncpy but make sure the resulting string is always 0 terminated: */
+/* writes SIZE chars, the [SIZE-1] char is always NUL (unless SIZE==0). */
 char *safe_strncpy(char *dst, const char *src, size_t size) FAST_FUNC;
 char *strncpy_IFNAMSIZ(char *dst, const char *src) FAST_FUNC;
 unsigned count_strstr(const char *str, const char *sub) FAST_FUNC;