Add a function for URL encoding file paths

src/common/utils.cpp

@@ -93,6 +93,79 @@ bool pid_running(pid_t pid) {
     }
 }
 
+std::string url_encode_path(std::string path) {
+    // We only need to escape a couple of special characters here. This is used
+    // in the notifications as well as in the XDND proxy. We encode the reserved
+    // characters mentioned here, with the exception of the forward slash:
+    // https://en.wikipedia.org/wiki/Percent-encoding#Reserved_characters
+    std::string escaped;
+    escaped.reserve(
+        static_cast<size_t>(static_cast<double>(path.size()) * 1.1));
+    for (const char& character : path) {
+        switch (character) {
+            case '!':
+                escaped.append("%21");
+                break;
+            case '#':
+                escaped.append("%23");
+                break;
+            case '$':
+                escaped.append("%24");
+                break;
+            case '%':
+                escaped.append("%25");
+                break;
+            case '&':
+                escaped.append("%26");
+                break;
+            case '\'':
+                escaped.append("%27");
+                break;
+            case '(':
+                escaped.append("%28");
+                break;
+            case ')':
+                escaped.append("%29");
+                break;
+            case '*':
+                escaped.append("%2A");
+                break;
+            case '+':
+                escaped.append("%2B");
+                break;
+            case ',':
+                escaped.append("%2C");
+                break;
+            case ':':
+                escaped.append("%3A");
+                break;
+            case ';':
+                escaped.append("%3B");
+                break;
+            case '=':
+                escaped.append("%3D");
+                break;
+            case '?':
+                escaped.append("%3F");
+                break;
+            case '@':
+                escaped.append("%40");
+                break;
+            case '[':
+                escaped.append("%5B");
+                break;
+            case ']':
+                escaped.append("%5D");
+                break;
+            default:
+                escaped.push_back(character);
+                break;
+        }
+    }
+
+    return escaped;
+}
+
 std::string xml_escape(std::string string) {
     // Implementation idea stolen from https://stackoverflow.com/a/5665377
     std::string escaped;

src/common/utils.h

@@ -133,6 +133,12 @@ bool is_watchdog_timer_disabled();
  */
 bool pid_running(pid_t pid);
 
+/**
+ * URL encode a file path. We won't escape forward slashes, and `path` should
+ * not yet include the `file://` prefix.
+ */
+std::string url_encode_path(std::string path);
+
 /**
  * Escape XML entities within a string. Used inside of desktop notifications.
  */