From c076f03dc49335a72e78c3b8a31f58edba1e5857 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sat, 18 Dec 2021 20:39:08 +0100
Subject: [PATCH 1/2] config: error out on empty key- or mouse binding

Closes #851
---
 CHANGELOG.md | 2 ++
 config.c     | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1904fd5d..9a972955 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -62,6 +62,8 @@
   CSI codes in the Kitty keyboard protocol.
 * Assertion in `shm.c:buffer_release()`
   (https://codeberg.org/dnkl/foot/issues/844).
+* Crash when setting a key- or mouse binding to the empty string
+  (https://codeberg.org/dnkl/foot/issues/851).
 
 
 ### Security
diff --git a/config.c b/config.c
index 50fb74e6..2b7ad378 100644
--- a/config.c
+++ b/config.c
@@ -1726,6 +1726,12 @@ value_to_key_combos(struct context *ctx, int action, struct argv *argv,
 
     }
 
+    if (idx == 0) {
+        LOG_CONTEXTUAL_ERR(
+            "empty binding not allowed (set to 'none' to unmap)");
+        goto err;
+    }
+
     remove_from_key_bindings_list(bindings, action, argv);
 
     bindings->arr = xrealloc(

From 454d4e22aaab3a7d4be3c1fe2f291630a952b1a0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sat, 18 Dec 2021 20:42:37 +0100
Subject: [PATCH 2/2] test: config: verify setting an empty key/mouse binding
 fails

---
 tests/test-config.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/tests/test-config.c b/tests/test-config.c
index 1e99b3c4..6a2edcb8 100644
--- a/tests/test-config.c
+++ b/tests/test-config.c
@@ -296,7 +296,16 @@ test_key_binding(struct context *ctx, bool (*parse_fun)(struct context *ctx),
     const int click_count = action % 3 + 1;
 
     /* Finally, generate the ‘value’ (e.g. “Control+shift+x”) */
-    char value[128];
+    char value[128] = {0};
+
+    ctx->key = key;
+    ctx->value = value;
+
+    /* First, try setting the empty string */
+    if (parse_fun(ctx)) {
+        BUG("[%s].%s=<empty>: did not fail to parse as expected",
+            ctx->section, ctx->key);
+    }
 
     switch (type) {
     case KEY_BINDING: {
@@ -319,9 +328,6 @@ test_key_binding(struct context *ctx, bool (*parse_fun)(struct context *ctx),
     }
     }
 
-    ctx->key = key;
-    ctx->value = value;
-
     if (!parse_fun(ctx)) {
         BUG("[%s].%s=%s failed to parse",
             ctx->section, ctx->key, ctx->value);