hush: add support for ${var/pattern/repl}, conditional on bash compat

function                                             old     new   delta
expand_vars_to_list                                 2386    2833    +447
expand_string_to_string                               69     110     +41
parse_dollar                                         681     721     +40
hush_main                                            963     945     -18
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 3/1 up/down: 528/-18)           Total: 510 bytes

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

1 files changed, 24 insertions, 0 deletions

diff --git a/shell/hush_test/hush-vars/var_bash2.tests b/shell/hush_test/hush-vars/var_bash2.tests
new file mode 100755
index 0000000..29c526c
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_bash2.tests
@@ -0,0 +1,24 @@
+var=abc123dcba123
+
+echo ${var/d/x}
+echo ${var/c/x}
+echo ${var//c/x}
+echo ${var/[123]/x}
+echo ${var//[123]/x}
+echo ${var/c*/x}
+echo ${var/*c/x}
+
+# must match longest match: result is "abx23"
+echo ${var/c*1/x}
+
+# empty replacement - 2nd slash can be omitted
+echo ${var/[123]}
+echo ${var//[123]}
+
+### ash doesn't support
+### # match only at the beginning:
+### echo ${var/#a/x}
+### echo ${var/#b/x} # should not match
+### echo ${var//#b/x} # should not match
+### # match only at the end:
+### echo ${var/%3/x}