filesystem: Rename a variable named "append" that is actually prepending.

(Strictly speaking, this was probably meant to be an "append" to the home/base
directory before the org/app name are appended to _that_, but it's definitely
added to the absolute start of the string on Emscripten, so might as well make
all of these match.

Reference PR #15262.

src/filesystem/emscripten/SDL_sysfilesystem.c

@@ -40,22 +40,22 @@ char *SDL_SYS_GetBasePath(void)
 char *SDL_SYS_GetPrefPath(const char *org, const char *app)
 {
     #ifdef SDL_EMSCRIPTEN_PERSISTENT_PATH_STRING
-    const char *append = SDL_EMSCRIPTEN_PERSISTENT_PATH_STRING;
+    const char *prepend = SDL_EMSCRIPTEN_PERSISTENT_PATH_STRING;
     #else
-    const char *append = "/libsdl";
+    const char *prepend = "/libsdl";
     #endif
     char *result;
     char *ptr = NULL;
-    const size_t len = SDL_strlen(append) + SDL_strlen(org) + SDL_strlen(app) + 4;
+    const size_t len = SDL_strlen(prepend) + SDL_strlen(org) + SDL_strlen(app) + 4;
     result = (char *)SDL_malloc(len);
     if (!result) {
         return NULL;
     }
 
     if (*org) {
-        SDL_snprintf(result, len, "%s/%s/%s/", append, org, app);
+        SDL_snprintf(result, len, "%s/%s/%s/", prepend, org, app);
     } else {
-        SDL_snprintf(result, len, "%s/%s/", append, app);
+        SDL_snprintf(result, len, "%s/%s/", prepend, app);
     }
 
     for (ptr = result + 1; *ptr; ptr++) {

src/filesystem/haiku/SDL_sysfilesystem.cc

@@ -69,19 +69,19 @@ char *SDL_SYS_GetPrefPath(const char *org, const char *app)
 {
     // !!! FIXME: is there a better way to do this?
     const char *home = SDL_getenv("HOME");
-    const char *append = "/config/settings/";
+    const char *prepend = "/config/settings/";
     size_t len = SDL_strlen(home);
 
     if (!len || (home[len - 1] == '/')) {
-        ++append; // home empty or ends with separator, skip the one from append
+        ++prepend; // home empty or ends with separator, skip the one from prepend
     }
-    len += SDL_strlen(append) + SDL_strlen(org) + SDL_strlen(app) + 3;
+    len += SDL_strlen(prepend) + SDL_strlen(org) + SDL_strlen(app) + 3;
     char *result = (char *) SDL_malloc(len);
     if (result) {
         if (*org) {
-            SDL_snprintf(result, len, "%s%s%s/%s/", home, append, org, app);
+            SDL_snprintf(result, len, "%s%s%s/%s/", home, prepend, org, app);
         } else {
-            SDL_snprintf(result, len, "%s%s%s/", home, append, app);
+            SDL_snprintf(result, len, "%s%s%s/", home, prepend, app);
         }
         create_directory(result, 0700);  // Haiku api: creates missing dirs
     }

src/filesystem/unix/SDL_sysfilesystem.c

@@ -266,7 +266,7 @@ char *SDL_SYS_GetPrefPath(const char *org, const char *app)
      * http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
      */
     const char *envr = SDL_getenv("XDG_DATA_HOME");
-    const char *append;
+    const char *prepend;
     char *result = NULL;
     char *ptr = NULL;
 
@@ -278,26 +278,26 @@ char *SDL_SYS_GetPrefPath(const char *org, const char *app)
             SDL_SetError("neither XDG_DATA_HOME nor HOME environment is set");
             return NULL;
         }
-        append = "/.local/share/";
+        prepend = "/.local/share/";
     } else {
-        append = "/";
+        prepend = "/";
     }
 
     size_t len = SDL_strlen(envr);
     if (envr[len - 1] == '/') {
-        append += 1;
+        prepend += 1;
     }
 
-    len += SDL_strlen(append) + SDL_strlen(org) + SDL_strlen(app) + 3;
+    len += SDL_strlen(prepend) + SDL_strlen(org) + SDL_strlen(app) + 3;
     result = (char *)SDL_malloc(len);
     if (!result) {
         return NULL;
     }
 
     if (*org) {
-        (void)SDL_snprintf(result, len, "%s%s%s/%s/", envr, append, org, app);
+        (void)SDL_snprintf(result, len, "%s%s%s/%s/", envr, prepend, org, app);
     } else {
-        (void)SDL_snprintf(result, len, "%s%s%s/", envr, append, app);
+        (void)SDL_snprintf(result, len, "%s%s%s/", envr, prepend, app);
     }
 
     for (ptr = result + 1; *ptr; ptr++) {