[PATCH] Compatibility with -Wunterminated-string-initialization in GCC 15

[Maxim Dounin]

# HG changeset patch
# User Maxim Dounin <mdounin at mdounin.ru>
# Date 1746113698 -10800
#      Thu May 01 18:34:58 2025 +0300
# Node ID 6d64b685bc7fbee88e31ce54a151de0deeaabdde
# Parent  b325ee44215f5e1ff102d7dbfc15ffe5b285bb9d
Compatibility with -Wunterminated-string-initialization in GCC 15.

Builds with recently released GCC 15 currently fail due to
-Wunterminated-string-initialization (introduced in -Wextra), which warns
about attempts to initialize a character array with a string literal
if the trailing NUL character doesn't fit (perfectly valid in C, but
might be unintentional).

Fix is to use arrays for initialization instead of string literals, or
switch to using character arrays of unknown size where appropriate.

diff --git a/src/event/quic/ngx_event_quic_protection.c b/src/event/quic/ngx_event_quic_protection.c
--- a/src/event/quic/ngx_event_quic_protection.c
+++ b/src/event/quic/ngx_event_quic_protection.c
@@ -122,9 +122,10 @@ ngx_quic_keys_set_initial_secret(ngx_qui
     ngx_quic_secret_t   *client, *server;
     ngx_quic_ciphers_t   ciphers;
 
-    static const uint8_t salt[20] =
-        "\x38\x76\x2c\xf7\xf5\x59\x34\xb3\x4d\x17"
-        "\x9a\xe6\xa4\xc8\x0c\xad\xcc\xbb\x7f\x0a";
+    static const uint8_t salt[20] = {
+        0x38, 0x76, 0x2c, 0xf7, 0xf5, 0x59, 0x34, 0xb3, 0x4d, 0x17,
+        0x9a, 0xe6, 0xa4, 0xc8, 0x0c, 0xad, 0xcc, 0xbb, 0x7f, 0x0a
+    };
 
     client = &keys->secrets[ssl_encryption_initial].client;
     server = &keys->secrets[ssl_encryption_initial].server;
@@ -936,10 +937,14 @@ ngx_quic_create_retry_packet(ngx_quic_he
     ngx_quic_ciphers_t   ciphers;
 
     /* 5.8.  Retry Packet Integrity */
-    static u_char     key_data[16] =
-        "\xbe\x0c\x69\x0b\x9f\x66\x57\x5a\x1d\x76\x6b\x54\xe3\x68\xc8\x4e";
-    static u_char     nonce[NGX_QUIC_IV_LEN] =
-        "\x46\x15\x99\xd3\x5d\x63\x2b\xf2\x23\x98\x25\xbb";
+    static u_char     key_data[16] = {
+        0xbe, 0x0c, 0x69, 0x0b, 0x9f, 0x66, 0x57, 0x5a, 0x1d, 0x76,
+        0x6b, 0x54, 0xe3, 0x68, 0xc8, 0x4e
+    };
+    static u_char     nonce[NGX_QUIC_IV_LEN] = {
+        0x46, 0x15, 0x99, 0xd3, 0x5d, 0x63, 0x2b, 0xf2, 0x23, 0x98,
+        0x25, 0xbb
+    };
     static ngx_str_t  in = ngx_string("");
 
     ad.data = res->data;
diff --git a/src/http/v2/ngx_http_v2_filter_module.c b/src/http/v2/ngx_http_v2_filter_module.c
--- a/src/http/v2/ngx_http_v2_filter_module.c
+++ b/src/http/v2/ngx_http_v2_filter_module.c
@@ -116,7 +116,7 @@ ngx_http_v2_header_filter(ngx_http_reque
     u_char                     addr[NGX_SOCKADDR_STRLEN];
 
 #if (NGX_HTTP_GZIP)
-    static const u_char accept_encoding[12] =
+    static const u_char accept_encoding[] =
         "\x8b\x84\x84\x2d\x69\x5b\x05\x44\x3c\x86\xaa\x6f";
 #endif
 
@@ -341,7 +341,7 @@ ngx_http_v2_header_filter(ngx_http_reque
 #if (NGX_HTTP_GZIP)
     if (r->gzip_vary) {
         if (clcf->gzip_vary) {
-            len += 1 + sizeof(accept_encoding);
+            len += 1 + sizeof(accept_encoding) - 1;
 
         } else {
             r->gzip_vary = 0;
@@ -568,7 +568,7 @@ ngx_http_v2_header_filter(ngx_http_reque
                        "http2 output header: \"vary: Accept-Encoding\"");
 
         *pos++ = ngx_http_v2_inc_indexed(NGX_HTTP_V2_VARY_INDEX);
-        pos = ngx_cpymem(pos, accept_encoding, sizeof(accept_encoding));
+        pos = ngx_cpymem(pos, accept_encoding, sizeof(accept_encoding) - 1);
     }
 #endif