wordsplit: optionally disable splitting of unexpandable variable and command refs

* include/wordsplit.h (WRDSO_NOVARSPLIT)
(WRDSO_NOCMDSPLIT): New options.
* src/wordsplit.c (scan_word): Treat any variable reference, even
containing whitespace, as a single word if WRDSO_NOVARSPLIT is set.
Ditto for commands and WRDSO_NOCMDSPLIT.
* tests/wordsplit.at: Add new tests.
* tests/wsp.c: Recognize novarsplit and nocmdsplit
options.
For future use: recognize bskeep_words, bskeep_quote, bskeep.

4 files changed, 38 insertions, 8 deletions

diff --git a/include/wordsplit.h b/include/wordsplit.h
index 3a7ab25..a175275 100644
--- a/include/wordsplit.h
+++ b/include/wordsplit.h
@@ -203,5 +203,3 @@ struct wordsplit
 #define WRDSO_DOTGLOB         0x00000004
-#if 0 /* Unused value */
-#define WRDSO_ARGV            0x00000008
-#endif
+/* Unused value:              0x00000008 */
 /* Keep backslash in unrecognized escape sequences in words */
@@ -222,2 +220,9 @@ struct wordsplit
 #define WRDSO_XESC_QUOTE      0x00000400
+/* Unused: 0x00000800 */
+/* Don't split variable references, even if they contain whitespace
+   (e.g. ${VAR:-foo bar}) */
+#define WRDSO_NOVARSPLIT     0x00001000
+/* Don't split commands, even containing whitespace, e.g.
+   $(echo foo bar) */
+#define WRDSO_NOCMDSPLIT     0x00002000
 
diff --git a/src/wordsplit.c b/src/wordsplit.c
index e979f27..521a1eb 100644
--- a/src/wordsplit.c
+++ b/src/wordsplit.c
@@ -2060,3 +2060,4 @@ scan_word (struct wordsplit *wsp, size_t start, int consume_all)
             {
-              if (!(wsp->ws_flags & WRDSF_NOVAR)
+              if ((!(wsp->ws_flags & WRDSF_NOVAR)
+                   || (wsp->ws_options & WRDSO_NOVARSPLIT))
                   && command[i+1] == '{'
@@ -2064,3 +2065,4 @@ scan_word (struct wordsplit *wsp, size_t start, int consume_all)
                 continue;
-              if (!(wsp->ws_flags & WRDSF_NOCMD)
+              if ((!(wsp->ws_flags & WRDSF_NOCMD)
+                   || (wsp->ws_options & WRDSO_NOCMDSPLIT))
                   && command[i+1] == '('
diff --git a/tests/wordsplit.at b/tests/wordsplit.at
index e3af703..1f2e80d 100644
--- a/tests/wordsplit.at
+++ b/tests/wordsplit.at
@@ -952,2 +952,20 @@ TOTAL: 3
 
+TESTWSP([variable nosplit],[],[novar novarsplit],
+[begin ${VAR:- a b} end],
+[NF: 3
+0: begin
+1: "${VAR:- a b}"
+2: end
+TOTAL: 3
+])
+
+TESTWSP([command nosplit],[],[nocmd nocmdsplit],
+[begin $(words a b) end],
+[NF: 3
+0: begin
+1: "$(words a b)"
+2: end
+TOTAL: 3
+])
+
 m4_popdef([TESTWSP])
diff --git a/tests/wsp.c b/tests/wsp.c
index cca3a36..bd13e63 100644
--- a/tests/wsp.c
+++ b/tests/wsp.c
@@ -63,5 +63,10 @@ struct kwd bool_keytab[] = {
 struct kwd opt_keytab[] = {
-  { "nullglob", WRDSO_NULLGLOB },
-  { "failglob", WRDSO_FAILGLOB },
-  { "dotglob",  WRDSO_DOTGLOB },
+  { "nullglob",     WRDSO_NULLGLOB },
+  { "failglob",     WRDSO_FAILGLOB },
+  { "dotglob",      WRDSO_DOTGLOB },
+  { "bskeep_words", WRDSO_BSKEEP_WORD },
+  { "bskeep_quote", WRDSO_BSKEEP_QUOTE },
+  { "bskeep",       WRDSO_BSKEEP_WORD|WRDSO_BSKEEP_QUOTE },
+  { "novarsplit",   WRDSO_NOVARSPLIT },
+  { "nocmdsplit",   WRDSO_NOCMDSPLIT },
   { NULL, 0 }