Cleanup: replace strncpy calls with BLI_strncpy

Prefer BLI_strncpy as it ensures the string is null terminated.

source/blender/blenkernel/intern/unit.c

@@ -1113,7 +1113,7 @@ bool BKE_unit_replace_string(
   /* Apply the default unit on the whole expression, this allows to handle nasty cases like
    * '2+2in'. */
   if (SNPRINTF(str_tmp, "(%s)*%.9g", str, default_unit->scalar) < sizeof(str_tmp)) {
-    strncpy(str, str_tmp, str_maxncpy);
+    BLI_strncpy(str, str_tmp, str_maxncpy);
   }
   else {
     /* BLI_snprintf would not fit into str_tmp, can't do much in this case.
@@ -1190,8 +1190,13 @@ void BKE_unit_name_to_alt(char *str, int str_maxncpy, const char *orig_str, int
         int len_name = 0;
 
         /* Copy everything before the unit. */
-        offset = (offset < str_maxncpy ? offset : str_maxncpy);
-        strncpy(str, orig_str, offset);
+        if (offset < str_maxncpy) {
+          memcpy(str, orig_str, offset);
+        }
+        else {
+          BLI_strncpy(str, orig_str, str_maxncpy);
+          offset = str_maxncpy;
+        }
 
         str += offset;
         orig_str += offset + strlen(unit->name_short);
@@ -1213,7 +1218,7 @@ void BKE_unit_name_to_alt(char *str, int str_maxncpy, const char *orig_str, int
   }
 
   /* Finally copy the rest of the string. */
-  strncpy(str, orig_str, str_maxncpy);
+  BLI_strncpy(str, orig_str, str_maxncpy);
 }
 
 double BKE_unit_closest_scalar(double value, int system, int type)

source/blender/blenlib/intern/winstuff.c

@@ -160,8 +160,7 @@ bool BLI_windows_register_blend_extension(const bool background)
     BLI_windows_get_executable_dir(InstallDir);
     GetSystemDirectory(SysDir, FILE_MAXDIR);
     const char *ThumbHandlerDLL = "BlendThumb.dll";
-    snprintf(
-        RegCmd, MAX_PATH * 2, "%s\\regsvr32 /s \"%s\\%s\"", SysDir, InstallDir, ThumbHandlerDLL);
+    SNPRINTF(RegCmd, "%s\\regsvr32 /s \"%s\\%s\"", SysDir, InstallDir, ThumbHandlerDLL);
     system(RegCmd);
   }
 #  endif

source/blender/editors/interface/interface_panel.cc

@@ -285,7 +285,7 @@ void UI_list_panel_unique_str(Panel *panel, char *r_name)
 {
   /* The panel sort-order will be unique for a specific panel type because the instanced
    * panel list is regenerated for every change in the data order / length. */
-  snprintf(r_name, INSTANCED_PANEL_UNIQUE_STR_LEN, "%d", panel->sortorder);
+  BLI_snprintf(r_name, INSTANCED_PANEL_UNIQUE_STR_LEN, "%d", panel->sortorder);
 }
 
 /**

source/blender/io/wavefront_obj/tests/obj_exporter_tests.cc

@@ -276,7 +276,7 @@ class obj_exporter_regression_test : public obj_exporter_test {
     BKE_tempdir_init(nullptr);
     std::string tempdir = std::string(BKE_tempdir_base());
     std::string out_file_path = tempdir + BLI_path_basename(golden_obj.c_str());
-    strncpy(params.filepath, out_file_path.c_str(), FILE_MAX - 1);
+    STRNCPY(params.filepath, out_file_path.c_str());
     params.blen_filepath = bfile->main->filepath;
     std::string golden_file_path = blender::tests::flags_test_asset_dir() + SEP_STR + golden_obj;
     BLI_path_split_dir_part(

source/blender/io/wavefront_obj/tests/obj_importer_tests.cc

@@ -16,6 +16,7 @@
 #include "BLI_listbase.h"
 #include "BLI_math_base.hh"
 #include "BLI_math_vector_types.hh"
+#include "BLI_string.h"
 
 #include "BLO_readfile.h"
 
@@ -74,7 +75,7 @@ class obj_importer_test : public BlendfileLoadingBaseTest {
 
     std::string obj_path = blender::tests::flags_test_asset_dir() +
                            SEP_STR "io_tests" SEP_STR "obj" SEP_STR + path;
-    strncpy(params.filepath, obj_path.c_str(), FILE_MAX - 1);
+    STRNCPY(params.filepath, obj_path.c_str());
     const size_t read_buffer_size = 650;
     importer_main(bfile->main, bfile->curscene, bfile->cur_view_layer, params, read_buffer_size);