From dad29bfae71d6cdd8397767362deef5b83487d87 Mon Sep 17 00:00:00 2001
From: pfeatherstone <45853521+pfeatherstone@users.noreply.github.com>
Date: Tue, 19 Sep 2023 13:12:02 +0100
Subject: [PATCH] Apple Clang complains about sprintf. Use snprintf instead.
 (#2862)

Co-authored-by: Your Name <you@example.com>
---
 dlib/gui_core/gui_core_kernel_2.cpp |  4 ++--
 dlib/gui_widgets/nativefont.h       | 11 +++++------
 dlib/http_client/http_client.cpp    |  4 ++--
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/dlib/gui_core/gui_core_kernel_2.cpp b/dlib/gui_core/gui_core_kernel_2.cpp
index d0c8879eb..be1cfb8d1 100644
--- a/dlib/gui_core/gui_core_kernel_2.cpp
+++ b/dlib/gui_core/gui_core_kernel_2.cpp
@@ -1614,9 +1614,9 @@ namespace dlib
             char **mlist;
             int mcount;
             char *def_str;
-            char fontset[256];
+            char fontset[256] = {0};
             const long native_font_height = 12;
-            sprintf(fontset, "-*-*-medium-r-normal--%lu-*-*-*-", native_font_height);
+            snprintf(fontset, sizeof(fontset), "-*-*-medium-r-normal--%lu-*-*-*-", native_font_height);
             x11_stuff.fs = XCreateFontSet(x11_stuff.globals->disp, fontset, &mlist, &mcount, &def_str);
             xpoint.x = 0;
             xpoint.y = 0;
diff --git a/dlib/gui_widgets/nativefont.h b/dlib/gui_widgets/nativefont.h
index 4850b79fe..69f0cfade 100644
--- a/dlib/gui_widgets/nativefont.h
+++ b/dlib/gui_widgets/nativefont.h
@@ -345,14 +345,13 @@ namespace nativefont
 
                         cmap = DefaultColormap(d, DefaultScreen(d));
                     }
-                    char fontset[256];
+                    char fontset[256] = {0};
                     {
-                        char *p = fontset;
-                        p += sprintf(fontset, "-*-*-%s-%c-normal--%d-*-*-*-%c",
-                                     bold ? "bold" : "medium", italic ? 'i' : 'r', height_want, fixed ? 'c' : 'p');
+                        int offset = snprintf(fontset, sizeof(fontset), "-*-*-%s-%c-normal--%d-*-*-*-%c",
+                                              bold ? "bold" : "medium", italic ? 'i' : 'r', height_want, fixed ? 'c' : 'p');
                         if (fixed){
-                            sprintf(p, ",-*-*-%s-%c-normal--%d-*-*-*-m",
-                                    bold ? "bold" : "medium", italic ? 'i' : 'r', height_want);
+                            snprintf(&fontset[offset], sizeof(fontset) - offset, ",-*-*-%s-%c-normal--%d-*-*-*-m",
+                                     bold ? "bold" : "medium", italic ? 'i' : 'r', height_want);
                         }
                     }
                     bool equal_font;
diff --git a/dlib/http_client/http_client.cpp b/dlib/http_client/http_client.cpp
index cb1105449..078cdfa4a 100644
--- a/dlib/http_client/http_client.cpp
+++ b/dlib/http_client/http_client.cpp
@@ -119,7 +119,7 @@ namespace dlib
 #ifdef __WXMSW__
         ::ltoa(header_value, buf, 10);
 #else
-        sprintf(buf, "%ld", header_value);
+        snprintf(buf, sizeof(buf), "%ld", header_value);
 #endif
         set_header(header_name, buf);
     }
@@ -154,7 +154,7 @@ namespace dlib
 #ifdef __WXMSW__
         ::ltoa(cookie_value, buf, 10);
 #else
-        sprintf(buf, "%ld", cookie_value);
+        snprintf(buf, sizeof(buf), "%ld", cookie_value);
 #endif
         set_cookie(cookie_name, buf);
     }