client API: change semantics for MPV_FORMAT_STRING

With mpv_set_property(h, "property", MPV_FORMAT_STRING, ptr), ptr now
has to be of type char** instead of char*. This makes it more consistent
with mpv_get_property() and also non-pointer formats, which will be
introduced in the following commits. mpv_set_property() of course does
not change its interface (only its implementation is adjusted to keep
its interface).

This also affects mpv_set_option(), but again not
mpv_set_option_string().

2 files changed, 19 insertions, 7 deletions

diff --git a/libmpv/client.h b/libmpv/client.h
index 901995ab29..2ad2fc4c0e 100644
--- a/libmpv/client.h
+++ b/libmpv/client.h
@@ -372,10 +372,16 @@ typedef enum mpv_format {
      *     printf("%s\n", result);
      *     mpv_free(result);
      *
+     * Or just use mpv_get_property_string().
+     *
      * Example for writing:
      *
      *     char *value = "the new value";
-     *     mpv_set_property(ctx, "property", MPV_FORMAT_STRING, (void *)value);
+     *     // yep, you pass the address to the variable
+     *     // (needed for symmetry with other types and mpv_get_property)
+     *     mpv_set_property(ctx, "property", MPV_FORMAT_STRING, &value);
+     *
+     * Or just use mpv_set_property_string().
      *
      */
     MPV_FORMAT_STRING           = 1,
@@ -673,7 +679,13 @@ typedef struct mpv_event_property {
      */
     mpv_format format;
     /**
-     * Received property value. Depends on the format.
+     * Received property value. Depends on the format. This is like the
+     * pointer argument passed to mpv_get_property().
+     *
+     * For example, for MPV_FORMAT_STRING you get the string with:
+     *
+     *    char *value = *(char **)(event_property->data);
+     *
      * Note that this is set to NULL if retrieving the property failed.
      * See mpv_event.error for the status.
      */
diff --git a/player/client.c b/player/client.c
index 39c28d2074..39d816c0bb 100644
--- a/player/client.c
+++ b/player/client.c
@@ -462,7 +462,7 @@ int mpv_set_option(mpv_handle *ctx, const char *name, mpv_format format,
     } else {
         if (format != MPV_FORMAT_STRING)
             return MPV_ERROR_OPTION_FORMAT;
-        const char *value = data;
+        const char *value = *(char **)data;
         int err = m_config_set_option0(ctx->mpctx->mconfig, name, value);
         switch (err) {
         case M_OPT_MISSING_PARAM:
@@ -481,7 +481,7 @@ int mpv_set_option(mpv_handle *ctx, const char *name, mpv_format format,
 
 int mpv_set_option_string(mpv_handle *ctx, const char *name, const char *data)
 {
-    return mpv_set_option(ctx, name, MPV_FORMAT_STRING, (void *)data);
+    return mpv_set_option(ctx, name, MPV_FORMAT_STRING, &data);
 }
 
 // Run a command in the playback thread.
@@ -635,7 +635,7 @@ int mpv_set_property(mpv_handle *ctx, const char *name, mpv_format format,
         .mpctx = ctx->mpctx,
         .name = name,
         .format = format,
-        .data = data,
+        .data = *(char **)data,
     };
     run_locked(ctx, setproperty_fn, &req);
     return req.status;
@@ -643,7 +643,7 @@ int mpv_set_property(mpv_handle *ctx, const char *name, mpv_format format,
 
 int mpv_set_property_string(mpv_handle *ctx, const char *name, const char *data)
 {
-    return mpv_set_property(ctx, name, MPV_FORMAT_STRING, (void *)data);
+    return mpv_set_property(ctx, name, MPV_FORMAT_STRING, &data);
 }
 
 int mpv_set_property_async(mpv_handle *ctx, uint64_t ud, const char *name,
@@ -657,7 +657,7 @@ int mpv_set_property_async(mpv_handle *ctx, uint64_t ud, const char *name,
         .mpctx = ctx->mpctx,
         .name = talloc_strdup(req, name),
         .format = MPV_FORMAT_STRING,
-        .data = talloc_strdup(req, data), // for now always a string
+        .data = talloc_strdup(req, *(char **)data), // for now always a string
         .reply_ctx = ctx,
         .userdata = ud,
     };