hush: IFS fixes

$ IFS=": "; x=" "; set x $x; for v; do echo "|$v|"; done
|x|
$ IFS=": "; x=":"; set x $x; for v; do echo "|$v|"; done
|x|
||

function                                             old     new   delta
run_pipe                                            1789    1870     +81
expand_on_ifs                                        310     361     +51
pseudo_exec_argv                                     588     591      +3
builtin_local                                         50      53      +3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 138/0)             Total: 138 bytes

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

diff --git a/shell/ash_test/ash-vars/var_wordsplit_ifs4.right b/shell/ash_test/ash-vars/var_wordsplit_ifs4.right
new file mode 100644 (file)
index 0000000..c27284c
--- /dev/null
+++ b/shell/ash_test/ash-vars/var_wordsplit_ifs4.right
@@ -0,0 +1,5 @@
+|x|
+Ok1:0
+|x|
+||
+Ok2:0

diff --git a/shell/ash_test/ash-vars/var_wordsplit_ifs4.tests b/shell/ash_test/ash-vars/var_wordsplit_ifs4.tests
new file mode 100755 (executable)
index 0000000..638bfbb
--- /dev/null
+++ b/shell/ash_test/ash-vars/var_wordsplit_ifs4.tests
@@ -0,0 +1,4 @@
+IFS=": "; x=" "; set x $x; for v; do echo "|$v|"; done
+echo Ok1:$?
+IFS=": "; x=":"; set x $x; for v; do echo "|$v|"; done
+echo Ok2:$?

diff --git a/shell/hush.c b/shell/hush.c
index 248364be2cac255a6a7858e2621f04cfcccecbb1..8e95a26a606b4365f797808b59c20e30d5d8cc46 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -930,6 +930,7 @@ struct globals {
        unsigned getopt_count;
 #endif
        const char *ifs;
+       char *ifs_whitespace; /* = G.ifs or malloced */
        const char *cwd;
        struct variable *top_var;
        char **expanded_assignments;
@@ -5696,10 +5697,20 @@ static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const cha
 
                /* We know str here points to at least one IFS char */
                last_is_ifs = 1;
-               str += strspn(str, G.ifs); /* skip IFS chars */
+               str += strspn(str, G.ifs_whitespace); /* skip IFS whitespace chars */
                if (!*str)  /* EOL - do not finalize word */
                        break;
 
+               if (G.ifs_whitespace != G.ifs /* usually false ($IFS is usually all whitespace), */
+                && strchr(G.ifs, *str)       /* the second check would fail */
+               ) {
+                       /* This is a non-whitespace $IFS char */
+                       /* Skip it and IFS whitespace chars, start new word */
+                       str++;
+                       str += strspn(str, G.ifs_whitespace);
+                       goto new_word;
+               }
+
                /* Start new word... but not always! */
                /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
                if (output->has_quoted_part
@@ -5710,6 +5721,7 @@ static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const cha
                 */
                 || (n > 0 && output->data[output->length - 1])
                ) {
+ new_word:
                        o_addchr(output, '\0');
                        debug_print_list("expand_on_ifs", output, n);
                        n = o_save_ptr(output, n);
@@ -8283,9 +8295,31 @@ static NOINLINE int run_pipe(struct pipe *pi)
        /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
         * Result should be 3 lines: q w e, qwe, q w e
         */
+       if (G.ifs_whitespace != G.ifs)
+               free(G.ifs_whitespace);
        G.ifs = get_local_var_value("IFS");
-       if (!G.ifs)
+       if (G.ifs) {
+               char *p;
+               G.ifs_whitespace = (char*)G.ifs;
+               p = skip_whitespace(G.ifs);
+               if (*p) {
+                       /* Not all $IFS is whitespace */
+                       char *d;
+                       int len = p - G.ifs;
+                       p = skip_non_whitespace(p);
+                       G.ifs_whitespace = xmalloc(len + strlen(p) + 1); /* can overestimate */
+                       d = mempcpy(G.ifs_whitespace, G.ifs, len);
+                       while (*p) {
+                               if (isspace(*p))
+                                       *d++ = *p;
+                               p++;
+                       }
+                       *d = '\0';
+               }
+       } else {
                G.ifs = defifs;
+               G.ifs_whitespace = (char*)G.ifs;
+       }
 
        IF_HUSH_JOB(pi->pgrp = -1;)
        pi->stopped_cmds = 0;

diff --git a/shell/hush_test/hush-vars/var_wordsplit_ifs4.right b/shell/hush_test/hush-vars/var_wordsplit_ifs4.right
new file mode 100644 (file)
index 0000000..c27284c
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_wordsplit_ifs4.right
@@ -0,0 +1,5 @@
+|x|
+Ok1:0
+|x|
+||
+Ok2:0

diff --git a/shell/hush_test/hush-vars/var_wordsplit_ifs4.tests b/shell/hush_test/hush-vars/var_wordsplit_ifs4.tests
new file mode 100755 (executable)
index 0000000..638bfbb
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_wordsplit_ifs4.tests
@@ -0,0 +1,4 @@
+IFS=": "; x=" "; set x $x; for v; do echo "|$v|"; done
+echo Ok1:$?
+IFS=": "; x=":"; set x $x; for v; do echo "|$v|"; done
+echo Ok2:$?