hush: allow { cmd } to not be terminated by semicolon in some cases

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

5 files changed, 58 insertions, 6 deletions

diff --git a/shell/ash_test/ash-misc/group_in_braces.right b/shell/ash_test/ash-misc/group_in_braces.right
new file mode 100644
index 000000000..a7064499b
--- /dev/null
+++ b/shell/ash_test/ash-misc/group_in_braces.right
@@ -0,0 +1,5 @@
+Zero:0
+Zero:0
+Zero:0
+Zero:0
+Zero:0
diff --git a/shell/ash_test/ash-misc/group_in_braces.tests b/shell/ash_test/ash-misc/group_in_braces.tests
new file mode 100755
index 000000000..f6571c35d
--- /dev/null
+++ b/shell/ash_test/ash-misc/group_in_braces.tests
@@ -0,0 +1,11 @@
+# Test cases where { cmd } does not require semicolon after "cmd"
+(exit 2); { { true; } }
+echo Zero:$?
+(exit 2); {(true)}
+echo Zero:$?
+(exit 2); { true | { true; } }
+echo Zero:$?
+(exit 2); { while false; do :; done }
+echo Zero:$?
+(exit 2); { case a in b) ;; esac }
+echo Zero:$?
diff --git a/shell/hush.c b/shell/hush.c
index 7c2f157b8..336de75ad 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3915,12 +3915,17 @@ static int parse_group(o_string *dest, struct parse_context *ctx,
                 command->cmd_type = CMD_SUBSHELL;
         } else {
                 /* bash does not allow "{echo...", requires whitespace */
-                ch = i_getch(input);
-                if (ch != ' ' && ch != '\t' && ch != '\n') {
+                ch = i_peek(input);
+                if (ch != ' ' && ch != '\t' && ch != '\n'
+                 && ch != '('   /* but "{(..." is allowed (without whitespace) */
+                ) {
                         syntax_error_unexpected_ch(ch);
                         return 1;
                 }
-                nommu_addchr(&ctx->as_string, ch);
+                if (ch != '(') {
+                        ch = i_getch(input);
+                        nommu_addchr(&ctx->as_string, ch);
+                }
         }
 
         {
@@ -4575,6 +4580,7 @@ static struct pipe *parse_stream(char **pstring,
                  || dest.has_quoted_part     /* ""{... - non-special */
                  || (next != ';'             /* }; - special */
                     && next != ')'           /* }) - special */
+                    && next != '('           /* {( - special */
                     && next != '&'           /* }& and }&& ... - special */
                     && next != '|'           /* }|| ... - special */
                     && !strchr(defifs, next) /* {word - non-special */
@@ -4657,17 +4663,31 @@ static struct pipe *parse_stream(char **pstring,
                  * Pathological example: { ""}; } should exec "}" cmd
                  */
                 if (ch == '}') {
-                        if (!IS_NULL_CMD(ctx.command) /* cmd } */
-                         || dest.length != 0 /* word} */
+                        if (dest.length != 0 /* word} */
                          || dest.has_quoted_part    /* ""} */
                         ) {
                                 goto ordinary_char;
                         }
+                        if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
+                                /* Generally, there should be semicolon: "cmd; }"
+                                 * However, bash allows to omit it if "cmd" is
+                                 * a group. Examples:
+                                 * { { echo 1; } }
+                                 * {(echo 1)}
+                                 * { echo 0 >&2 | { echo 1; } }
+                                 * { while false; do :; done }
+                                 * { case a in b) ;; esac }
+                                 */
+                                if (ctx.command->group)
+                                        goto term_group;
+                                goto ordinary_char;
+                        }
                         if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
+                                /* Can't be an end of {cmd}, skip the check */
                                 goto skip_end_trigger;
                         /* else: } does terminate a group */
                 }
-
+ term_group:
                 if (end_trigger && end_trigger == ch
                  && (ch != ';' || heredoc_cnt == 0)
 #if ENABLE_HUSH_CASE
diff --git a/shell/hush_test/hush-misc/group_in_braces.right b/shell/hush_test/hush-misc/group_in_braces.right
new file mode 100644
index 000000000..a7064499b
--- /dev/null
+++ b/shell/hush_test/hush-misc/group_in_braces.right
@@ -0,0 +1,5 @@
+Zero:0
+Zero:0
+Zero:0
+Zero:0
+Zero:0
diff --git a/shell/hush_test/hush-misc/group_in_braces.tests b/shell/hush_test/hush-misc/group_in_braces.tests
new file mode 100755
index 000000000..f6571c35d
--- /dev/null
+++ b/shell/hush_test/hush-misc/group_in_braces.tests
@@ -0,0 +1,11 @@
+# Test cases where { cmd } does not require semicolon after "cmd"
+(exit 2); { { true; } }
+echo Zero:$?
+(exit 2); {(true)}
+echo Zero:$?
+(exit 2); { true | { true; } }
+echo Zero:$?
+(exit 2); { while false; do :; done }
+echo Zero:$?
+(exit 2); { case a in b) ;; esac }
+echo Zero:$?