PATCH: Add $ZLE_STATE in zle widgets

[Frank Terbeck <ft@xxxxxxxxxxxxxxxxxxx>]

This is the $OVERWRITE idea converted to a string $ZLE_STATE, that may
contain more than one attribute. Currently it only handles the status of
the overwrite bit (!insmode).
---
 Doc/Zsh/zle.yo       |    7 +++++++
 Src/Zle/zle_params.c |   22 ++++++++++++++++++++++
 2 files changed, 29 insertions(+), 0 deletions(-)

diff --git a/Doc/Zsh/zle.yo b/Doc/Zsh/zle.yo
index 0e2fea5..ab5ea3f 100644
--- a/Doc/Zsh/zle.yo
+++ b/Doc/Zsh/zle.yo
@@ -854,6 +854,13 @@ executed; the second argument that followed tt(zle -C) when the widget was
 defined.  This is the name of a builtin completion widget.  For widgets
 defined with tt(zle -N) this is set to the empty string.  Read-only.
 )
+vindex(ZLE_STATE)
+item(tt(ZLE_STATE) (scalar))(
+Contains a set of sub-strings that describe the current tt(zle) state.
+Currently, this can only contain `tt(overwrite)' which is the case if
+tt(zle) will overwrite existing characters if the cursor is not at the
+end of a buffer line and new characters are entered.  Read-only.
+)
 enditem()
 
 subsect(Special Widgets)
diff --git a/Src/Zle/zle_params.c b/Src/Zle/zle_params.c
index 2883c0f..ee8814d 100644
--- a/Src/Zle/zle_params.c
+++ b/Src/Zle/zle_params.c
@@ -76,6 +76,8 @@ static const struct gsu_scalar widgetfunc_gsu =
 { get_widgetfunc, nullstrsetfn, zleunsetfn };
 static const struct gsu_scalar widgetstyle_gsu =
 { get_widgetstyle, nullstrsetfn, zleunsetfn };
+static const struct gsu_scalar zle_state_gsu =
+{ get_zle_state, nullstrsetfn, zleunsetfn };
 
 static const struct gsu_integer bufferlines_gsu =
 { get_bufferlines, NULL, zleunsetfn };
@@ -134,6 +136,7 @@ static struct zleparam {
     { "WIDGET", PM_SCALAR | PM_READONLY, GSU(widget_gsu), NULL },
     { "WIDGETFUNC", PM_SCALAR | PM_READONLY, GSU(widgetfunc_gsu), NULL },
     { "WIDGETSTYLE", PM_SCALAR | PM_READONLY, GSU(widgetstyle_gsu), NULL },
+    { "ZLE_STATE", PM_SCALAR | PM_READONLY, GSU(zle_state_gsu), NULL },
     { NULL, 0, NULL, NULL }
 };
 
@@ -695,3 +698,22 @@ get_context(UNUSED(Param pm))
 	break;
     }
 }
+
+/**/
+static char *
+get_zle_state(UNUSED(Param pm))
+{
+    char *zle_state;
+
+    /*
+     * When additional substrings are added, they should be kept in
+     * alphabetical order, so the user can easily match against this
+     * parameter: if [[ $ZLE_STATE == *bar*foo*zonk* ]]; then ...; fi
+     */
+    zle_state = dupstring("");
+    if (!insmode) {
+	zle_state = dyncat(zle_state, "overwrite");
+    }
+
+    return zle_state;
+}
-- 
1.7.2.rc2