[gnome-characters] libgc: Fix crasher with some GCC configurations

[Daiki Ueno <dueno src gnome org>]

commit 00877953360f4a42c9f3c9cd11b4a16843494e00
Author: Bastien Nocera <hadess hadess net>
Date:   Sat Apr 21 15:07:17 2018 +0200

    libgc: Fix crasher with some GCC configurations
    
    const variables are not supposed to be writable, and trying to
    initialise the various "const" blocks caused SEGVs. Remove the const
    modifier as it's incorrect.
    
    The valgrind output for this crash is clear, "Bad permissions":
    ==11056== Process terminating with default action of signal 11 (SIGSEGV): dumping core
    ==11056==  Bad permissions for mapped region at address 0x28C91360
    ==11056==    at 0x28C8D0AB: init_blocks (gc.c:926)
    ==11056==    by 0x28C8E46B: gc_character_iter_init_for_related (gc.c:938)
    ==11056==    by 0x28C8E46B: gc_search_context_search (gc.c:1124)

 lib/gc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)
---
diff --git a/lib/gc.c b/lib/gc.c
index ad27d27..bcad500 100644
--- a/lib/gc.c
+++ b/lib/gc.c
@@ -26,21 +26,21 @@ static size_t all_block_count;
 
 #define LATIN_BLOCK_SIZE 4
 static gsize latin_blocks_initialized;
-static const uc_block_t latin_blocks[LATIN_BLOCK_SIZE];
+static uc_block_t latin_blocks[LATIN_BLOCK_SIZE];
 static const ucs4_t latin_block_starters[LATIN_BLOCK_SIZE] =
   { 0x0000, 0x0080, 0x0100, 0x0180 };
 static size_t latin_block_count;
 
 #define HIRAGANA_BLOCK_SIZE 1
 static gsize hiragana_blocks_initialized;
-static const uc_block_t hiragana_blocks[HIRAGANA_BLOCK_SIZE];
+static uc_block_t hiragana_blocks[HIRAGANA_BLOCK_SIZE];
 static const ucs4_t hiragana_block_starters[HIRAGANA_BLOCK_SIZE] =
   { 0x3040 };
 static size_t hiragana_block_count;
 
 #define KATAKANA_BLOCK_SIZE 2
 static gsize katakana_blocks_initialized;
-static const uc_block_t katakana_blocks[KATAKANA_BLOCK_SIZE];
+static uc_block_t katakana_blocks[KATAKANA_BLOCK_SIZE];
 static const ucs4_t katakana_block_starters[KATAKANA_BLOCK_SIZE] =
   { 0x30A0, 0x31F0 };
 static size_t katakana_block_count;
@@ -372,10 +372,10 @@ gc_character_iter_init_for_category (GcCharacterIter *iter,
 
     case GC_CATEGORY_LETTER_LATIN:
       {
-        static const uc_script_t *latin_scripts[2];
-        latin_scripts[0] = uc_script ('A');
+        uc_script_t *latin_scripts[2];
+        latin_scripts[0] = (uc_script_t *)uc_script ('A');
         latin_scripts[1] = NULL;
-        gc_character_iter_init_for_scripts (iter, latin_scripts);
+        gc_character_iter_init_for_scripts (iter, (const uc_script_t * const *)latin_scripts);
         return;
       }
 
@@ -529,7 +529,7 @@ gchar *
 gc_character_name (gunichar uc)
 {
   const uc_block_t *block;
-  static const uc_block_t *cjk_blocks[6];
+  static uc_block_t *cjk_blocks[6];
   static gsize cjk_blocks_initialized = 0;
   gsize i;
 
@@ -915,7 +915,7 @@ populate_related_characters (GcCharacterIter *iter)
 }
 
 static size_t
-init_blocks (const uc_block_t *blocks, const ucs4_t *starters, size_t size)
+init_blocks (uc_block_t *blocks, const ucs4_t *starters, size_t size)
 {
   size_t i, count;