hush: readability improvements.

 fix some more obscure bugs.
 a new redir4.tests is known to fail.

5 files changed, 232 insertions, 97 deletions

diff --git a/shell/hush.c b/shell/hush.c
index ac2410c48..21590adfb 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -341,7 +341,11 @@ typedef enum redir_type {
         REDIRECT_HEREDOC   = 4,
         REDIRECT_IO        = 5,
         REDIRECT_HEREDOC2  = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
-        REDIRFD_CLOSE = -3,
+
+        REDIRFD_CLOSE      = -3,
+        REDIRFD_SYNTAX_ERR = -2,
+        REDIRFD_TO_FILE    = -1, /* otherwise, rd_fd if redirected to rd_dup */
+
         HEREDOC_SKIPTABS = 1,
         HEREDOC_QUOTED   = 2,
 } redir_type;
@@ -2427,6 +2431,7 @@ static int setup_redirects(struct command *prog, int squirrel[])
 
         for (redir = prog->redirects; redir; redir = redir->next) {
                 if (redir->rd_type == REDIRECT_HEREDOC2) {
+                        /* rd_fd<<HERE case */
                         if (squirrel && redir->rd_fd < 3) {
                                 squirrel[redir->rd_fd] = dup(redir->rd_fd);
                         }
@@ -2438,15 +2443,16 @@ static int setup_redirects(struct command *prog, int squirrel[])
                         continue;
                 }
 
-                if (redir->rd_dup == -1) {
+                if (redir->rd_dup == REDIRFD_TO_FILE) {
+                        /* rd_fd<*>file case (<*> is <,>,>>,<>) */
                         char *p;
                         if (redir->rd_filename == NULL) {
                                 /* Something went wrong in the parse.
                                  * Pretend it didn't happen */
+                                bb_error_msg("bug in redirect parse");
                                 continue;
                         }
                         mode = redir_table[redir->rd_type].mode;
-//TODO: check redir for names like '\\'
                         p = expand_string_to_string(redir->rd_filename);
                         openfd = open_or_warn(p, mode);
                         free(p);
@@ -2457,6 +2463,7 @@ static int setup_redirects(struct command *prog, int squirrel[])
                                 return 1;
                         }
                 } else {
+                        /* rd_fd<*>rd_dup or rd_fd<*>- cases */
                         openfd = redir->rd_dup;
                 }
 
@@ -2469,7 +2476,7 @@ static int setup_redirects(struct command *prog, int squirrel[])
                                 close(redir->rd_fd);
                         } else {
                                 xdup2(openfd, redir->rd_fd);
-                                if (redir->rd_dup == -1)
+                                if (redir->rd_dup == REDIRFD_TO_FILE)
                                         close(openfd);
                         }
                 }
@@ -3963,17 +3970,6 @@ static int done_word(o_string *word, struct parse_context *ctx)
                 debug_printf_parse("done_word return 0: true null, ignored\n");
                 return 0;
         }
-        /* If this word wasn't an assignment, next ones definitely
-         * can't be assignments. Even if they look like ones. */
-        if (word->o_assignment != DEFINITELY_ASSIGNMENT
-         && word->o_assignment != WORD_IS_KEYWORD
-        ) {
-                word->o_assignment = NOT_ASSIGNMENT;
-        } else {
-                if (word->o_assignment == DEFINITELY_ASSIGNMENT)
-                        command->assignment_cnt++;
-                word->o_assignment = MAYBE_ASSIGNMENT;
-        }
 
         if (ctx->pending_redirect) {
                 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
@@ -3989,29 +3985,47 @@ static int done_word(o_string *word, struct parse_context *ctx)
                  * the expansion would result in one word."
                  */
                 ctx->pending_redirect->rd_filename = xstrdup(word->data);
+                /* Cater for >\file case:
+                 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
+                 * Same with heredocs:
+                 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
+                 */
+                unbackslash(ctx->pending_redirect->rd_filename);
+                /* Is it <<"HEREDOC"? */
                 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
                  && word->o_quoted
                 ) {
                         ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
                 }
-                word->o_assignment = NOT_ASSIGNMENT;
                 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
         } else {
-                /* "{ echo foo; } echo bar" - bad */
-                /* NB: bash allows e.g.:
-                 * if true; then { echo foo; } fi
-                 * while if false; then false; fi do break; done
-                 * and disallows:
-                 * while if false; then false; fi; do; break; done
-                 * TODO? */
+                /* If this word wasn't an assignment, next ones definitely
+                 * can't be assignments. Even if they look like ones. */
+                if (word->o_assignment != DEFINITELY_ASSIGNMENT
+                 && word->o_assignment != WORD_IS_KEYWORD
+                ) {
+                        word->o_assignment = NOT_ASSIGNMENT;
+                } else {
+                        if (word->o_assignment == DEFINITELY_ASSIGNMENT)
+                                command->assignment_cnt++;
+                        word->o_assignment = MAYBE_ASSIGNMENT;
+                }
+
                 if (command->group) {
+                        /* "{ echo foo; } echo bar" - bad */
+                        /* NB: bash allows e.g.:
+                         * if true; then { echo foo; } fi
+                         * while if false; then false; fi do break; done
+                         * and disallows:
+                         * while if false; then false; fi; do; break; done
+                         * TODO? */
                         syntax_error_at(word->data);
                         debug_printf_parse("done_word return 1: syntax error, "
                                         "groups and arglists don't mix\n");
                         return 1;
                 }
 #if HAS_KEYWORDS
-#if ENABLE_HUSH_CASE
+# if ENABLE_HUSH_CASE
                 if (ctx->ctx_dsemicolon
                  && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
                 ) {
@@ -4019,12 +4033,12 @@ static int done_word(o_string *word, struct parse_context *ctx)
                         /* ctx->ctx_res_w = RES_MATCH; */
                         ctx->ctx_dsemicolon = 0;
                 } else
-#endif
+# endif
                 if (!command->argv /* if it's the first word... */
-#if ENABLE_HUSH_LOOPS
+# if ENABLE_HUSH_LOOPS
                  && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
                  && ctx->ctx_res_w != RES_IN
-#endif
+# endif
                 ) {
                         debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
                         if (reserved_word(word, ctx)) {
@@ -4090,20 +4104,23 @@ static int done_word(o_string *word, struct parse_context *ctx)
 
 /* Peek ahead in the input to find out if we have a "&n" construct,
  * as in "2>&1", that represents duplicating a file descriptor.
- * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
- * -2 (syntax error), -1 if no & was seen, or the number found.
+ * Return:
+ * REDIRFD_CLOSE if >&- "close fd" construct is seen,
+ * REDIRFD_SYNTAX_ERR if syntax error,
+ * REDIRFD_TO_FILE if no & was seen,
+ * or the number found.
  */
 #if BB_MMU
-#define redirect_dup_num(as_string, input) \
-        redirect_dup_num(input)
+#define parse_redir_right_fd(as_string, input) \
+        parse_redir_right_fd(input)
 #endif
-static int redirect_dup_num(o_string *as_string, struct in_str *input)
+static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
 {
         int ch, d, ok;
 
         ch = i_peek(input);
         if (ch != '&')
-                return -1;
+                return REDIRFD_TO_FILE;
 
         ch = i_getch(input);  /* get the & */
         nommu_addchr(as_string, ch);
@@ -4127,10 +4144,10 @@ static int redirect_dup_num(o_string *as_string, struct in_str *input)
 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
 
         bb_error_msg("ambiguous redirect");
-        return -2;
+        return REDIRFD_SYNTAX_ERR;
 }
 
-/* Return code is 0 normally, 1 if a syntax error is detected
+/* Return code is 0 normal, 1 if a syntax error is detected
  */
 static int parse_redirect(struct parse_context *ctx,
                 int fd,
@@ -4142,12 +4159,12 @@ static int parse_redirect(struct parse_context *ctx,
         struct redir_struct **redirp;
         int dup_num;
 
-        dup_num = -1;
+        dup_num = REDIRFD_TO_FILE;
         if (style != REDIRECT_HEREDOC) {
-                /* Check for a '2>&1' type redirect */
-                dup_num = redirect_dup_num(&ctx->as_string, input);
-                if (dup_num == -2)
-                        return 1;  /* syntax error */
+                /* Check for a '>&1' type redirect */
+                dup_num = parse_redir_right_fd(&ctx->as_string, input);
+                if (dup_num == REDIRFD_SYNTAX_ERR)
+                        return 1;
         } else {
                 int ch = i_peek(input);
                 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
@@ -4158,7 +4175,7 @@ static int parse_redirect(struct parse_context *ctx,
                 }
         }
 
-        if (style == REDIRECT_OVERWRITE && dup_num == -1) {
+        if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
                 int ch = i_peek(input);
                 if (ch == '|') {
                         /* >|FILE redirect ("clobbering" >).
@@ -4185,7 +4202,7 @@ static int parse_redirect(struct parse_context *ctx,
                                 redir_table[style].descrip);
 
         redir->rd_dup = dup_num;
-        if (style != REDIRECT_HEREDOC && dup_num != -1) {
+        if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
                 /* Erik had a check here that the file descriptor in question
                  * is legit; I postpone that to "run time"
                  * A "-" representation of "close me" shows up as a -3 here */
@@ -4862,9 +4879,6 @@ static int parse_stream_dquoted(o_string *as_string,
                  * only when followed by one of the following characters:
                  * $, `, ", \, or <newline>.  A double quote may be quoted
                  * within double quotes by preceding it with a backslash.
-                 * If enabled, history expansion will be performed unless
-                 * an ! appearing in double quotes is escaped using
-                 * a backslash. The backslash preceding the ! is not removed."
                  */
                 if (strchr("$`\"\\", next) != NULL) {
                         o_addqchr(dest, i_getch(input));
@@ -5081,17 +5095,71 @@ static struct pipe *parse_stream(char **pstring,
                 if (is_ifs)
                         continue;
 
-                if (dest.o_assignment == MAYBE_ASSIGNMENT) {
-                        /* ch is a special char and thus this word
-                         * cannot be an assignment */
-                        dest.o_assignment = NOT_ASSIGNMENT;
-                }
-
                 next = '\0';
                 if (ch != '\n') {
                         next = i_peek(input);
                 }
 
+                /* Catch <, > before deciding whether this word is
+                 * an assignment. a=1 2>z b=2: b=2 is still assignment */
+                switch (ch) {
+                case '>':
+                        redir_fd = redirect_opt_num(&dest);
+                        if (done_word(&dest, &ctx)) {
+                                goto parse_error;
+                        }
+                        redir_style = REDIRECT_OVERWRITE;
+                        if (next == '>') {
+                                redir_style = REDIRECT_APPEND;
+                                ch = i_getch(input);
+                                nommu_addchr(&ctx.as_string, ch);
+                        }
+#if 0
+                        else if (next == '(') {
+                                syntax_error(">(process) not supported");
+                                goto parse_error;
+                        }
+#endif
+                        if (parse_redirect(&ctx, redir_fd, redir_style, input))
+                                goto parse_error;
+                        continue; /* back to top of while (1) */
+                case '<':
+                        redir_fd = redirect_opt_num(&dest);
+                        if (done_word(&dest, &ctx)) {
+                                goto parse_error;
+                        }
+                        redir_style = REDIRECT_INPUT;
+                        if (next == '<') {
+                                redir_style = REDIRECT_HEREDOC;
+                                heredoc_cnt++;
+                                debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
+                                ch = i_getch(input);
+                                nommu_addchr(&ctx.as_string, ch);
+                        } else if (next == '>') {
+                                redir_style = REDIRECT_IO;
+                                ch = i_getch(input);
+                                nommu_addchr(&ctx.as_string, ch);
+                        }
+#if 0
+                        else if (next == '(') {
+                                syntax_error("<(process) not supported");
+                                goto parse_error;
+                        }
+#endif
+                        if (parse_redirect(&ctx, redir_fd, redir_style, input))
+                                goto parse_error;
+                        continue; /* back to top of while (1) */
+                }
+
+                if (dest.o_assignment == MAYBE_ASSIGNMENT
+                 /* check that we are not in word in "a=1 2>word b=1": */
+                 && !ctx.pending_redirect
+                ) {
+                        /* ch is a special char and thus this word
+                         * cannot be an assignment */
+                        dest.o_assignment = NOT_ASSIGNMENT;
+                }
+
                 switch (ch) {
                 case '#':
                         if (dest.length == 0) {
@@ -5171,52 +5239,6 @@ static struct pipe *parse_stream(char **pstring,
                         break;
                 }
 #endif
-                case '>':
-                        redir_fd = redirect_opt_num(&dest);
-                        if (done_word(&dest, &ctx)) {
-                                goto parse_error;
-                        }
-                        redir_style = REDIRECT_OVERWRITE;
-                        if (next == '>') {
-                                redir_style = REDIRECT_APPEND;
-                                ch = i_getch(input);
-                                nommu_addchr(&ctx.as_string, ch);
-                        }
-#if 0
-                        else if (next == '(') {
-                                syntax_error(">(process) not supported");
-                                goto parse_error;
-                        }
-#endif
-                        if (parse_redirect(&ctx, redir_fd, redir_style, input))
-                                goto parse_error;
-                        break;
-                case '<':
-                        redir_fd = redirect_opt_num(&dest);
-                        if (done_word(&dest, &ctx)) {
-                                goto parse_error;
-                        }
-                        redir_style = REDIRECT_INPUT;
-                        if (next == '<') {
-                                redir_style = REDIRECT_HEREDOC;
-                                heredoc_cnt++;
-                                debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
-                                ch = i_getch(input);
-                                nommu_addchr(&ctx.as_string, ch);
-                        } else if (next == '>') {
-                                redir_style = REDIRECT_IO;
-                                ch = i_getch(input);
-                                nommu_addchr(&ctx.as_string, ch);
-                        }
-#if 0
-                        else if (next == '(') {
-                                syntax_error("<(process) not supported");
-                                goto parse_error;
-                        }
-#endif
-                        if (parse_redirect(&ctx, redir_fd, redir_style, input))
-                                goto parse_error;
-                        break;
                 case ';':
 #if ENABLE_HUSH_CASE
  case_semi:
diff --git a/shell/hush_test/hush-misc/redir1.right b/shell/hush_test/hush-misc/redir1.right
index ac90b4a0a..15515d1af 100644
--- a/shell/hush_test/hush-misc/redir1.right
+++ b/shell/hush_test/hush-misc/redir1.right
@@ -1,3 +1,5 @@
+Test 0:  var:ok
+File created:ok
 Test 1:  var:ok
 File created:ok
 Test 2:  var:ok
diff --git a/shell/hush_test/hush-misc/redir1.tests b/shell/hush_test/hush-misc/redir1.tests
index 7e204514c..70e9e17f0 100755
--- a/shell/hush_test/hush-misc/redir1.tests
+++ b/shell/hush_test/hush-misc/redir1.tests
@@ -1,5 +1,11 @@
 rm shell_test_$$ 2>/dev/null
 var=bad
+>shell_test_$$ var=ok
+echo "Test 0:  var:$var"
+test -f shell_test_$$ && echo "File created:ok"
+
+rm shell_test_$$ 2>/dev/null
+var=bad
 var=ok >shell_test_$$
 echo "Test 1:  var:$var"
 test -f shell_test_$$ && echo "File created:ok"
diff --git a/shell/hush_test/hush-misc/redir4.right b/shell/hush_test/hush-misc/redir4.right
new file mode 100644
index 000000000..ada6c2d85
--- /dev/null
+++ b/shell/hush_test/hush-misc/redir4.right
@@ -0,0 +1,25 @@
+shell_test
+\shell_test
+\shell_test
+\shell_test
+Here1
+Ok1
+Here2
+Ok2
+Here3
+Ok3
+Here4
+Ok4
+How with variable refs
+shell_test_1
+\shell_test_1
+\shell_test_1
+\shell_test_1
+Here1
+Ok1
+Here2
+Ok2
+Here3
+Ok3
+Here4
+Ok4
diff --git a/shell/hush_test/hush-misc/redir4.tests b/shell/hush_test/hush-misc/redir4.tests
new file mode 100755
index 000000000..ac2a44166
--- /dev/null
+++ b/shell/hush_test/hush-misc/redir4.tests
@@ -0,0 +1,80 @@
+rm *shell_test* 2>/dev/null
+
+>\shell_test
+echo *shell_test*
+rm *shell_test*
+
+>\\shell_test
+echo *shell_test*
+rm *shell_test*
+
+>"\shell_test"
+echo *shell_test*
+rm *shell_test*
+
+>"\\shell_test"
+echo *shell_test*
+rm *shell_test*
+
+
+cat <<\shell_test
+Here1
+shell_test
+echo Ok1
+
+cat <<\\shell_test
+Here2
+\shell_test
+echo Ok2
+
+cat <<"\shell_test"
+Here3
+\shell_test
+echo Ok3
+
+cat <<"\\shell_test"
+Here4
+\shell_test
+echo Ok4
+
+
+echo How with variable refs
+i=1
+
+
+>\shell_test_$i
+echo *shell_test*
+rm *shell_test*
+
+>\\shell_test_$i
+echo *shell_test*
+rm *shell_test*
+
+>"\shell_test_$i"
+echo *shell_test*
+rm *shell_test*
+
+>"\\shell_test_$i"
+echo *shell_test*
+rm *shell_test*
+
+
+cat <<\shell_test_$i
+Here1
+shell_test_$i
+echo Ok1
+
+cat <<\\shell_test_$i
+Here2
+\shell_test_$i
+echo Ok2
+
+cat <<"\shell_test_$i"
+Here3
+\shell_test_$i
+echo Ok3
+
+cat <<"\\shell_test_$i"
+Here4
+\shell_test_$i
+echo Ok4