hush: fix var_bash5.tests failure

function                                             old     new   delta
expand_one_var                                      1513    1552     +39
expand_pseudo_dquoted                                118     135     +17
expand_string_to_string                              110     126     +16
setup_heredoc                                        298     308     +10
expand_and_evaluate_arith                             69      79     +10
parse_stream_dquoted                                 233     241      +8
setup_redirects                                      220     225      +5
run_list                                             956     961      +5
expand_assignments                                    76      81      +5
run_pipe                                            1587    1590      +3
parse_stream                                        2371    2374      +3
builtin_umask                                        132     133      +1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 12/0 up/down: 122/0)            Total: 122 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

3 files changed, 54 insertions, 26 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 942e72ad0..f49a39b0f 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -4335,7 +4335,7 @@ static struct pipe *parse_stream(char **pstring,
 /*** Execution routines ***/
 
 /* Expansion can recurse, need forward decls: */
-static char *expand_string_to_string(const char *str);
+static char *expand_string_to_string(const char *str, int do_unbackslash);
 static int process_command_subs(o_string *dest, const char *s);
 
 /* expand_strvec_to_strvec() takes a list of strings, expands
@@ -4387,7 +4387,7 @@ static int expand_on_ifs(o_string *output, int n, const char *str)
  * Returns malloced string.
  * As an optimization, we return NULL if expansion is not needed.
  */
-static char *expand_pseudo_dquoted(const char *str, int dquoted)
+static char *expand_pseudo_dquoted(const char *str, int dquoted, int do_unbackslash)
 {
         char *exp_str;
         struct in_str input;
@@ -4408,7 +4408,7 @@ static char *expand_pseudo_dquoted(const char *str, int dquoted)
         setup_string_in_str(&input, str);
         parse_stream_dquoted(NULL, &dest, &input, EOF, dquoted);
         //bb_error_msg("'%s' -> '%s'", str, dest.data);
-        exp_str = expand_string_to_string(dest.data);
+        exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
         //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
         o_free_unsafe(&dest);
         return exp_str;
@@ -4424,7 +4424,7 @@ static arith_t expand_and_evaluate_arith(const char *arg, int *errcode_p)
         hooks.lookupvar = get_local_var_value;
         hooks.setvar = set_local_var_from_halves;
         //hooks.endofname = endofname;
-        exp_str = expand_pseudo_dquoted(arg, /*dquoted:*/ 1);
+        exp_str = expand_pseudo_dquoted(arg, /*dquoted:*/ 1, /*unbackslash:*/ 1);
         res = arith(exp_str ? exp_str : arg, errcode_p, &hooks);
         free(exp_str);
         return res;
@@ -4594,8 +4594,7 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
 //TODO: avoid xstrdup unless needed
 // (see HACK ALERT below for an example)
                                 val = to_be_freed = xstrdup(val);
-//TODO: fix expansion rules:
-                                exp_exp_word = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1);
+                                exp_exp_word = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1, /*unbackslash:*/ 1);
                                 if (exp_exp_word)
                                         exp_word = exp_exp_word;
                                 loc = scan_and_match(to_be_freed, exp_word, scan_flags);
@@ -4631,9 +4630,8 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
                                  * v='a bz'; echo ${v/a*z/\z}    prints "z"
                                  * (note that a*z _pattern_ is never globbed!)
                                  */
-//TODO: fix expansion rules:
                                 char *pattern, *repl, *t;
-                                pattern = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1);
+                                pattern = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 0, /*unbackslash:*/ 0);
                                 if (!pattern)
                                         pattern = xstrdup(exp_word);
                                 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
@@ -4641,7 +4639,7 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
                                 exp_word = p;
                                 p = strchr(p, SPECIAL_VAR_SYMBOL);
                                 *p = '\0';
-                                repl = expand_pseudo_dquoted(exp_word, /*dquoted:*/ arg0 & 0x80);
+                                repl = expand_pseudo_dquoted(exp_word, /*dquoted:*/ arg0 & 0x80, /*unbackslash:*/ 1);
                                 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
                                 /* HACK ALERT. We depend here on the fact that
                                  * G.global_argv and results of utoa and get_local_var_value
@@ -4726,7 +4724,7 @@ static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, cha
                         debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
                                         (exp_save == ':') ? "true" : "false", use_word);
                         if (use_word) {
-                                to_be_freed = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1);
+                                to_be_freed = expand_pseudo_dquoted(exp_word, /*dquoted:*/ 1, /*unbackslash:*/ 1);
                                 if (to_be_freed)
                                         exp_word = to_be_freed;
                                 if (exp_op == '?') {
@@ -4998,30 +4996,35 @@ static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
  * NB: should NOT do globbing!
  * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
  */
-static char *expand_string_to_string(const char *str)
+static char *expand_string_to_string(const char *str, int do_unbackslash)
 {
         char *argv[2], **list;
 
+        debug_printf_expand("string_to_string<='%s'\n", str);
         /* This is generally an optimization, but it also
          * handles "", which otherwise trips over !list[0] check below.
          * (is this ever happens that we actually get str="" here?)
          */
         if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
                 //TODO: Can use on strings with \ too, just unbackslash() them?
-                debug_printf_expand("string_to_string(fast)='%s'\n", str);
+                debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
                 return xstrdup(str);
         }
 
         argv[0] = (char*)str;
         argv[1] = NULL;
-        list = expand_variables(argv, EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD);
+        list = expand_variables(argv, do_unbackslash
+                        ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
+                        : EXP_FLAG_SINGLEWORD
+        );
         if (HUSH_DEBUG)
                 if (!list[0] || list[1])
                         bb_error_msg_and_die("BUG in varexp2");
         /* actually, just move string 2*sizeof(char*) bytes back */
         overlapping_strcpy((char*)list, list[0]);
-        unbackslash((char*)list);
-        debug_printf_expand("string_to_string='%s'\n", (char*)list);
+        if (do_unbackslash)
+                unbackslash((char*)list);
+        debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
         return (char*)list;
 }
 
@@ -5056,7 +5059,7 @@ static char **expand_assignments(char **argv, int count)
         G.expanded_assignments = p = NULL;
         /* Expand assignments into one string each */
         for (i = 0; i < count; i++) {
-                G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i]));
+                G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
         }
         G.expanded_assignments = NULL;
         return p;
@@ -5465,7 +5468,7 @@ static void setup_heredoc(struct redir_struct *redir)
 
         expanded = NULL;
         if (!(redir->rd_dup & HEREDOC_QUOTED)) {
-                expanded = expand_pseudo_dquoted(heredoc, /*dquoted:*/ 1);
+                expanded = expand_pseudo_dquoted(heredoc, /*dquoted:*/ 1, /*unbackslash:*/ 1);
                 if (expanded)
                         heredoc = expanded;
         }
@@ -5565,7 +5568,7 @@ static int setup_redirects(struct command *prog, int squirrel[])
                                 continue;
                         }
                         mode = redir_table[redir->rd_type].mode;
-                        p = expand_string_to_string(redir->rd_filename);
+                        p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
                         openfd = open_or_warn(p, mode);
                         free(p);
                         if (openfd < 0) {
@@ -6516,7 +6519,7 @@ static NOINLINE int run_pipe(struct pipe *pi)
                         if (G_x_mode)
                                 bb_putchar_stderr('+');
                         while (*argv) {
-                                char *p = expand_string_to_string(*argv);
+                                char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
                                 if (G_x_mode)
                                         fprintf(stderr, " %s", p);
                                 debug_printf_exec("set shell var:'%s'->'%s'\n",
@@ -7020,7 +7023,7 @@ static int run_list(struct pipe *pi)
                         /* all prev words didn't match, does this one match? */
                         argv = pi->cmds->argv;
                         while (*argv) {
-                                char *pattern = expand_string_to_string(*argv);
+                                char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
                                 /* TODO: which FNM_xxx flags to use? */
                                 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
                                 free(pattern);
diff --git a/shell/hush_test/hush-vars/var_bash5.right b/shell/hush_test/hush-vars/var_bash5.right
index 278ed3228..1990902b2 100644
--- a/shell/hush_test/hush-vars/var_bash5.right
+++ b/shell/hush_test/hush-vars/var_bash5.right
@@ -1,4 +1,11 @@
-a/
-a/d
-a/e/f
+1 a/
+2 a/d
+3 a/e/f
+4 a\
+5 a\d
+6 a\e\f
+7 a\\
+8 a\\d
+9 a\\e\\f
+a ab
 Done: 0
diff --git a/shell/hush_test/hush-vars/var_bash5.tests b/shell/hush_test/hush-vars/var_bash5.tests
index 7f482a554..5748b4ac7 100755
--- a/shell/hush_test/hush-vars/var_bash5.tests
+++ b/shell/hush_test/hush-vars/var_bash5.tests
@@ -4,8 +4,26 @@
 v='a/b/c'
 s='b/c'
 r='e/f'
-echo "${v/$s}"
-echo "${v/$s/d}"
-echo "${v/$s/$r}"
+echo "1 ${v/$s}"
+echo "2 ${v/$s/d}"
+echo "3 ${v/$s/$r}"
+
+v='a\b\c'
+s='b\\c'
+r='e\f'
+echo "4 ${v/$s}"
+echo "5 ${v/$s/d}"
+echo "6 ${v/$s/$r}"
+
+v='a\\b\\c'
+s='b\\\\c'
+r='e\\f'
+echo "7 ${v/$s}"
+echo "8 ${v/$s/d}"
+echo "9 ${v/$s/$r}"
+
+v='a-$a-\t-\\-\"-\`-\--\z-\*-\?-b'
+s='-$a-\\t-\\\\-\\"-\\`-\\--\\z-\\\*-\\\?-'
+echo "a ${v/$s}"
 
 echo Done: $?