proj.ini: do not set 'only_best_default' at all; and when set to on/o…

…ff, disable related warnings

data/proj.ini

@@ -16,13 +16,14 @@ cache_size_MB = 300
 cache_ttl_sec = 86400
 
 ; Can be set to on so that by default the lack of a known resource files needed
-; for the best transformation PROJ would normally use causes an error. This
-; default value itself is overriden by the PROJ_ONLY_BEST_DEFAULT environment
+; for the best transformation PROJ would normally use causes an error, or off
+; to accept missing resource files without errors or warnings.
+; This default value itself is overriden by the PROJ_ONLY_BEST_DEFAULT environment
 ; variable if set, and then by the ONLY_BEST setting that can be
 ; passed to the proj_create_crs_to_crs() method, or with the --only-best
 ; option of the cs2cs program.
 ; (added in PROJ 9.2)
-only_best_default = off
+; only_best_default = on
 
 ; Filename of the Certificate Authority (CA) bundle.
 ; Can be overriden with the PROJ_CURL_CA_BUNDLE / CURL_CA_BUNDLE environment variable.

src/4D_api.cpp

@@ -1942,7 +1942,7 @@ PJ  *proj_create_crs_to_crs_from_pj (PJ_CONTEXT *ctx, const PJ *source_crs, cons
     double accuracy = -1;
     bool allowBallparkTransformations = true;
     bool forceOver = false;
-    bool warnIfBestTransformationNotAvailable = true;
+    bool warnIfBestTransformationNotAvailable = ctx->warnIfBestTransformationNotAvailableDefault;
     bool errorIfBestTransformationNotAvailable = ctx->errorIfBestTransformationNotAvailableDefault;
     for (auto iter = options; iter && iter[0]; ++iter) {
         const char *value;

src/ctx.cpp

@@ -151,6 +151,7 @@ pj_ctx::pj_ctx(const pj_ctx& other) :
     last_errno(0),
     debug_level(other.debug_level),
     errorIfBestTransformationNotAvailableDefault(other.errorIfBestTransformationNotAvailableDefault),
+    warnIfBestTransformationNotAvailableDefault(other.warnIfBestTransformationNotAvailableDefault),
     logger(other.logger),
     logger_app_data(other.logger_app_data),
     cpp_context(other.cpp_context ? other.cpp_context->clone(this) : nullptr),

src/filemanager.cpp

@@ -1823,6 +1823,7 @@ void pj_load_ini(PJ_CONTEXT *ctx) {
     // from environment first
     const char *proj_only_best_default = getenv("PROJ_ONLY_BEST_DEFAULT");
     if (proj_only_best_default && proj_only_best_default[0] != '\0') {
+        ctx->warnIfBestTransformationNotAvailableDefault = false;
         ctx->errorIfBestTransformationNotAvailableDefault =
             ci_equal(proj_only_best_default, "ON") ||
             ci_equal(proj_only_best_default, "YES") ||
@@ -1890,6 +1891,7 @@ void pj_load_ini(PJ_CONTEXT *ctx) {
                 ctx->ca_bundle_path = value;
             } else if (proj_only_best_default == nullptr &&
                        key == "only_best_default") {
+                ctx->warnIfBestTransformationNotAvailableDefault = false;
                 ctx->errorIfBestTransformationNotAvailableDefault =
                     ci_equal(value, "ON") ||
                     ci_equal(value, "YES") ||

src/proj_internal.h

@@ -697,6 +697,7 @@ struct pj_ctx{
     int     last_errno = 0;
     int     debug_level = PJ_LOG_ERROR;
     bool errorIfBestTransformationNotAvailableDefault = false;
+    bool warnIfBestTransformationNotAvailableDefault = true;
     void    (*logger)(void *, int, const char *) = nullptr;
     void    *logger_app_data = nullptr;
     struct projCppContext* cpp_context = nullptr; /* internal context for C++ code */