ash: improve set -x to quote strings as necessary

Basen on the patch from Martijn Dekker <martijn@inlv.org>

function                                             old     new   delta
evalcommand                                         1161    1302    +141
maybe_single_quote                                     -      60     +60
getoptscmd                                           527     546     +19
readtoken1                                          2819    2823      +4
localcmd                                             366     364      -2
evaltreenr                                           495     479     -16
evaltree                                             495     479     -16
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 3/3 up/down: 224/-34)           Total: 190 bytes

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

2 files changed, 24 insertions, 0 deletions

diff --git a/shell/ash_test/ash-quoting/mode_x.right b/shell/ash_test/ash-quoting/mode_x.right
new file mode 100644
index 000000000..c2dd3550c
--- /dev/null
+++ b/shell/ash_test/ash-quoting/mode_x.right
@@ -0,0 +1,10 @@
++ var1=val
++ var2='one two'
++ true '%s\n' one 'two '"'"'three' four
++ this=command
++ 'this=command'
+./mode_x.tests: line 1: this=command: not found
++ true
++ true
++ 'if' true
+./mode_x.tests: line 1: if: not found
diff --git a/shell/ash_test/ash-quoting/mode_x.tests b/shell/ash_test/ash-quoting/mode_x.tests
new file mode 100755
index 000000000..16dae3f4b
--- /dev/null
+++ b/shell/ash_test/ash-quoting/mode_x.tests
@@ -0,0 +1,14 @@
+set -x
+
+var1=val
+var2='one two'
+true %s\\n one "two 'three" four
+
+# assignment:
+this=command
+# NOT assignment, +x code should show it quoted:
+"this=command"
+
+if true; then true; fi
+# +x code should quote 'if' here:
+"if" true