ash: add comment explaining last change

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

1 files changed, 6 insertions, 6 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 5381f34eb..83a8e77f9 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -6756,6 +6756,10 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
         //              p, varname, strloc, subtype, startloc, varflags, quotes);
 
 #if BASH_PATTERN_SUBST
+        /* For "${v/pattern/repl}", we must find the delimiter _before_
+         * argstr() call expands possible variable references in pattern:
+         * think about "v=a; a=a/; echo ${v/$a/r}" case.
+         */
         repl = NULL;
         if (subtype == VSREPLACE || subtype == VSREPLACEALL) {
                 /* Find '/' and replace with NUL */
@@ -6770,11 +6774,8 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
                                 *repl = '\0';
                                 break;
                         }
-                        if ((unsigned char)*repl == CTLESC
-                         && repl[1]
-                        ) {
+                        if ((unsigned char)*repl == CTLESC && repl[1])
                                 repl++;
-                        }
                         repl++;
                 }
         }
@@ -6941,11 +6942,10 @@ subevalvar(char *p, char *varname, int strloc, int subtype,
 
                 if (!repl) {
                         //bb_error_msg("str9:'%s' slash_pos:%d", str, slash_pos);
+                        repl = nullstr;
                         if (slash_pos >= 0) {
                                 repl = str + slash_pos;
                                 *repl++ = '\0';
-                        } else {
-                                repl = nullstr;
                         }
                 }
                 //bb_error_msg("str:'%s' repl:'%s'", str, repl);