3 files changed, 21 insertions, 2 deletions

diff --git a/dmenu b/dmenu
index 4a32929..9595929 100755
--- a/dmenu
+++ b/dmenu
diff --git a/dmenu.1 b/dmenu.1
index 762f707..29d3c6f 100644
--- a/dmenu.1
+++ b/dmenu.1
@@ -3,7 +3,7 @@
 dmenu \- dynamic menu
 .SH SYNOPSIS
 .B dmenu
-.RB [ \-bfivP ]
+.RB [ \-bfirvP ]
 .RB [ \-l
 .IR lines ]
 .RB [ \-m
@@ -49,6 +49,8 @@ dmenu matches menu items case insensitively.
 .TP
 .B \-P
 dmenu will not directly display the keyboard input, but instead replace it with dots. All data from stdin will be ignored.
+.B \-r
+dmenu will reject any input which would result in no matching option left.
 .TP
 .BI \-l " lines"
 dmenu lists items vertically, with the given number of lines.
diff --git a/dmenu.c b/dmenu.c
index b1f1d3d..c5cce46 100644
--- a/dmenu.c
+++ b/dmenu.c
@@ -43,6 +43,7 @@ static char *embed;
 static int bh, mw, mh;
 static int inputw = 0, promptw, passwd = 0;
 static int lrpad; /* sum of left and right padding */
+static int reject_no_match = 0;
 static size_t cursor;
 static struct item *items = NULL;
 static struct item *matches, *matchend;
@@ -426,12 +427,26 @@ insert(const char *str, ssize_t n)
 {
         if (strlen(text) + n > sizeof text - 1)
                 return;
+
+        static char last[BUFSIZ] = "";
+        if(reject_no_match) {
+                /* store last text value in case we need to revert it */
+                memcpy(last, text, BUFSIZ);
+        }
+
         /* move existing text out of the way, insert new text, and update cursor */
         memmove(&text[cursor + n], &text[cursor], sizeof text - cursor - MAX(n, 0));
         if (n > 0)
                 memcpy(&text[cursor], str, n);
         cursor += n;
         match();
+
+        if(!matches && reject_no_match) {
+                /* revert to last text value if theres no match */
+                memcpy(text, last, BUFSIZ);
+                cursor -= n;
+                match();
+        }
 }
 
 static size_t
@@ -858,7 +873,7 @@ setup(void)
 static void
 usage(void)
 {
-        die("usage: dmenu [-bfivP] [-l lines] [-p prompt] [-fn font] [-m monitor]\n"
+        die("usage: dmenu [-bfirvP] [-l lines] [-p prompt] [-fn font] [-m monitor]\n"
             "             [-nb color] [-nf color] [-sb color] [-sf color] [-w windowid]");
 }
 
@@ -884,6 +899,8 @@ main(int argc, char *argv[])
                         fstrstr = cistrstr;
                 } else if (!strcmp(argv[i], "-P"))   /* is the input a password */
                         passwd = 1;
+                else if (!strcmp(argv[i], "-r")) /* reject input which results in no match */
+                        reject_no_match = 1;
                 else if (i + 1 == argc)
                         usage();
                 /* these options take one argument */