gnome-shell/0001-st-theme-Reuse-stylesheets-if-possible.patch

115 lines
3.8 KiB
Diff

From 4ad7120d0188dcf21146da02637f82bac2ac7ad6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Wed, 29 Jan 2025 02:46:44 +0100
Subject: [PATCH] st/theme: Reuse stylesheets if possible
The following happens when processing an `@import()` rule:
1. `_st_theme_resolve_url()` to resolve file
2. `insert_stylesheet()` to track file/sheet
a. take ownership of file/sheet (ref)
b. use file as key in `stylesheets_by_file` hash table
c. use file as value in `files_by_stylesheet` hash table
3. release reference to file
This leads to a refcount error when importing a file that
was already parsed before:
1. file start with refcount 1
2. `insert_stylesheet()`
a. increases refcount to 2
b. inserting into `stylesheets_by_file` *decreases* the
passed-in key if the key already exists
c. `files_by_stylesheet` now tracks a file with recount 1
3. releases the last reference to file
The file object tracked in `files_by_stylesheet` is now invalid,
and accessing it results in a crash.
Avoid this issue by reusing existing stylesheets, so we don't insert
a stylesheet that's already tracked.
As a side-effect, this also saves us from re-parsing the same file
unnecessarily.
Closes: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/7306
---
src/st/st-theme.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/src/st/st-theme.c b/src/st/st-theme.c
index 9867ee1510..9ad99e2b1a 100644
--- a/src/st/st-theme.c
+++ b/src/st/st-theme.c
@@ -244,6 +244,27 @@ insert_stylesheet (StTheme *theme,
g_hash_table_insert (theme->files_by_stylesheet, stylesheet, file);
}
+static CRStyleSheet *
+resolve_stylesheet (StTheme *theme,
+ GFile *file,
+ GError **error)
+{
+ CRStyleSheet *sheet;
+
+ sheet = g_hash_table_lookup (theme->stylesheets_by_file, file);
+ if (sheet)
+ {
+ cr_stylesheet_ref (sheet);
+ return sheet;
+ }
+
+ sheet = parse_stylesheet (file, error);
+ if (sheet)
+ insert_stylesheet (theme, file, sheet);
+
+ return sheet;
+}
+
/**
* st_theme_load_stylesheet:
* @theme: a #StTheme
@@ -261,13 +282,12 @@ st_theme_load_stylesheet (StTheme *theme,
{
CRStyleSheet *stylesheet;
- stylesheet = parse_stylesheet (file, error);
+ stylesheet = resolve_stylesheet (theme, file, error);
if (!stylesheet)
return FALSE;
stylesheet->app_data = GUINT_TO_POINTER (TRUE);
- insert_stylesheet (theme, file, stylesheet);
cr_stylesheet_ref (stylesheet);
theme->custom_stylesheets = g_slist_prepend (theme->custom_stylesheets, stylesheet);
g_signal_emit (theme, signals[STYLESHEETS_CHANGED], 0);
@@ -884,6 +904,7 @@ add_matched_properties (StTheme *a_this,
if (import_rule->sheet == NULL)
{
+ CRStyleSheet *sheet = NULL;
GFile *file = NULL;
if (import_rule->url->stryng && import_rule->url->stryng->str)
@@ -891,13 +912,12 @@ add_matched_properties (StTheme *a_this,
file = _st_theme_resolve_url (a_this,
a_nodesheet,
import_rule->url->stryng->str);
- import_rule->sheet = parse_stylesheet (file, NULL);
+ sheet = resolve_stylesheet (a_this, file, NULL);
}
- if (import_rule->sheet)
+ if (sheet)
{
- insert_stylesheet (a_this, file, import_rule->sheet);
- /* refcount of stylesheets starts off at zero, so we don't need to unref! */
+ import_rule->sheet = sheet;
}
else
{
--
2.48.1