c-api: add missing SVGZ error enum

crates/c-api/ResvgQt.h

@@ -71,6 +71,8 @@ static QString errorToString(const int err)
             return QString();
         case RESVG_ERROR_NOT_AN_UTF8_STR :
             return QLatin1String("The SVG content has not an UTF-8 encoding.");
+        case RESVG_ERROR_SVGZ_UNSUPPORTED :
+            return QLatin1String("SVGZ decoding is unsupported.");
         case RESVG_ERROR_FILE_OPEN_FAILED :
             return QLatin1String("Failed to read the file.");
         case RESVG_ERROR_MALFORMED_GZIP :

crates/c-api/lib.rs

@@ -22,7 +22,7 @@ pub enum resvg_error {
     OK = 0,
     /// Only UTF-8 content are supported.
     NOT_AN_UTF8_STR,
-    /// `resvg` must be compiled with SVGZ decoding support.
+    /// SVGZ decoding is unsupported.
     SVGZ_UNSUPPORTED,
     /// Failed to open the provided file.
     FILE_OPEN_FAILED,

crates/c-api/resvg.h

@@ -30,6 +30,10 @@ typedef enum {
      * Only UTF-8 content are supported.
      */
     RESVG_ERROR_NOT_AN_UTF8_STR,
+    /**
+     * SVGZ decoding is unsupported.
+     */
+    RESVG_ERROR_SVGZ_UNSUPPORTED,
     /**
      * Failed to open the provided file.
      */