Print error message for invalid color strings

include/components/config.hpp

@@ -105,6 +105,9 @@ class config {
       return dereference<T>(move(section), move(key), move(string_value), move(result));
     } catch (const key_error& err) {
       return default_value;
+    } catch (const value_error& err) {
+      m_log.err("Invalid value for \"%s.%s\", using default value (reason: %s)", section, key, err.what());
+      return default_value;
     }
   }
 
@@ -165,6 +168,9 @@ class config {
         }
       } catch (const key_error& err) {
         break;
+      } catch (const value_error& err) {
+        m_log.err("Invalid value in list \"%s.%s\", using list as-is (reason: %s)", section, key, err.what());
+        return default_value;
       }
     }
 

include/events/signal_emitter.hpp

@@ -34,7 +34,7 @@ class signal_emitter {
         }
       }
     } catch (const std::exception& e) {
-      logger::make().err(e.what());
+      logger::make().err("Signal receiver raised an exception: %s", e.what());
     }
 
     return false;

src/components/config.cpp

@@ -201,7 +201,13 @@ chrono::duration<double> config::convert(string&& value) const {
 
 template <>
 rgba config::convert(string&& value) const {
-  return rgba{value};
+  rgba ret{value};
+
+  if (!ret.has_color()) {
+    throw value_error("\"" + value + "\" is an invalid color value.");
+  }
+
+  return ret;
 }
 
 template <>

src/components/parser.cpp

@@ -224,6 +224,10 @@ rgba parser::parse_color(const string& s, rgba fallback) {
     rgba ret = rgba{s};
 
     if (!ret.has_color() || ret.m_type == rgba::ALPHA_ONLY) {
+      logger::make().warn(
+          "Invalid color in formatting tag detected: \"%s\", using fallback \"%s\". This is an issue with one of your "
+          "formatting tags. If it is not, please report this as a bug.",
+          s, static_cast<string>(fallback));
       return fallback;
     }
 

src/utils/color.cpp

@@ -58,7 +58,6 @@ rgba::rgba(string hex) {
   hex = normalize_hex(hex);
 
   if (hex.length() == 0) {
-    // TODO we need a way to inform the user that their color was malformed
     m_value = 0;
     m_type = NONE;
   } else if (hex.length() == 2) {