[evolution-data-server] camel-debug: Copy cached backtrace symbol strings

[Milan Crha <mcrha src gnome org>]

commit 554b408ac3214926cd6160502578c32f9a8da409
Author: Milan Crha <mcrha redhat com>
Date:   Thu Feb 25 09:14:24 2021 +0100

    camel-debug: Copy cached backtrace symbol strings
    
    Needed when the symbol comes from a module and this module is unloaded,
    then the const char strings returned from dwfl_getmodules() are invalidated.

 src/camel/camel-debug.c | 46 ++++++++++++++++++++++++++++++----------------
 1 file changed, 30 insertions(+), 16 deletions(-)
---
diff --git a/src/camel/camel-debug.c b/src/camel/camel-debug.c
index ce12a4466..680569130 100644
--- a/src/camel/camel-debug.c
+++ b/src/camel/camel-debug.c
@@ -522,50 +522,64 @@ addr_lookup_dwfl (gpointer addr,
 }
 
 typedef struct _SymbolData {
-       const gchar *func_name;
-       const gchar *file_path;
+       gchar *func_name;
+       gchar *file_path;
        gint lineno;
 } SymbolData;
 
+static void
+symbol_data_free (gpointer ptr)
+{
+       SymbolData *sd = ptr;
+
+       if (sd) {
+               g_free (sd->func_name);
+               g_free (sd->file_path);
+               g_free (sd);
+       }
+}
+
 static const gchar *
 addr_lookup (gpointer addr,
-             const gchar **file_path,
-             gint *lineno,
+             const gchar **out_file_path,
+             gint *out_lineno,
              const gchar *fallback)
 {
        static GHashTable *symbols_cache = NULL;
        static GMutex mutex;
-       SymbolData *sd, sd_local;
+       SymbolData *sd;
+       const gchar *func_name, *file_path = NULL;
+       gint lineno = -1;
 
        g_mutex_lock (&mutex);
        if (symbols_cache) {
                sd = g_hash_table_lookup (symbols_cache, addr);
                if (sd) {
                        g_mutex_unlock (&mutex);
-                       *file_path = sd->file_path;
-                       *lineno = sd->lineno;
+                       *out_file_path = sd->file_path;
+                       *out_lineno = sd->lineno;
 
                        return sd->func_name;
                }
        }
 
-       sd_local.func_name = addr_lookup_dwfl (addr, &sd_local.file_path, &sd_local.lineno, fallback);
-       if (sd_local.func_name) {
+       func_name = addr_lookup_dwfl (addr, &file_path, &lineno, fallback);
+       if (func_name) {
                if (!symbols_cache)
-                       symbols_cache = g_hash_table_new_full (NULL, NULL, NULL, g_free);
+                       symbols_cache = g_hash_table_new_full (NULL, NULL, NULL, symbol_data_free);
                sd = g_new (SymbolData, 1);
-               sd->func_name = sd_local.func_name;
-               sd->file_path = sd_local.file_path;
-               sd->lineno = sd_local.lineno;
+               sd->func_name = g_strdup (func_name);
+               sd->file_path = g_strdup (file_path);
+               sd->lineno = lineno;
                g_hash_table_insert (symbols_cache, addr, sd);
        }
 
        g_mutex_unlock (&mutex);
 
-       *file_path = sd_local.file_path;
-       *lineno = sd_local.lineno;
+       *out_file_path = file_path;
+       *out_lineno = lineno;
 
-       return sd_local.func_name;
+       return func_name;
 }
 
 #endif /* HAVE_BACKTRACE_SYMBOLS */