Merge 542bef343a into 9e6098432a

- Print additional context to make troubleshooting easier.
- Add the placeholder where the error occurred as a prefix to the error message.
- Use sentence case for all error messages.

core/string/ustring.cpp

@@ -5882,7 +5882,7 @@ String String::sprintf(const Array &values, bool *error) const {
 					} else {
 						if (c == '0' && min_chars == 0) {
 							if (left_justified) {
-								WARN_PRINT("[%0]: The \"0\" flag is ignored with \"-\" flag in string formatting.");
+								WARN_PRINT("[%%0]: The \"0\" flag is ignored with \"-\" flag in string formatting.");
 							} else {
 								pad_with_zeros = true;
 							}
@@ -5904,7 +5904,7 @@ String String::sprintf(const Array &values, bool *error) const {
 
 				case '*': { // Dynamic width, based on value.
 					if (value_index >= values.size()) {
-						return vformat("[%*]: Not enough arguments for string formatting (%d provided, but more were expected). Check for extraneous %% placeholders or missing arguments.", value_index);
+						return vformat("[%%*]: Not enough arguments for string formatting (%d provided, but more were expected). Check for extraneous %% placeholders or missing arguments.", value_index);
 					}
 
 					Variant::Type value_type = values[value_index].get_type();
@@ -5912,7 +5912,7 @@ String String::sprintf(const Array &values, bool *error) const {
 							value_type != Variant::VECTOR2 && value_type != Variant::VECTOR2I &&
 							value_type != Variant::VECTOR3 && value_type != Variant::VECTOR3I &&
 							value_type != Variant::VECTOR4 && value_type != Variant::VECTOR4I) {
-						return vformat("[%*]: A number (int/float) or a vector type (Vector2/3/4/2i/3i/4i) is required, but a %s was provided.", Variant().get_type_name(values[value_index].get_type()));
+						return vformat("[%%*]: A number (int/float) or a vector type (Vector2/3/4/2i/3i/4i) is required, but a %s was provided.", Variant::get_type_name(value_type));
 					}
 
 					int size = values[value_index];

tests/core/string/test_string.h

@@ -1229,7 +1229,7 @@ TEST_CASE("[String] sprintf") {
 	args.push_back("sc");
 	output = format.sprintf(args, &error);
 	REQUIRE(error);
-	CHECK(output == "[%c]: Requires a number or a single-character string, but a string of 2 characters was provided.");
+	CHECK(output == "[%c]: A number or a single-character string is required, but a string of 2 characters was provided.");
 
 	// Character bad type.
 	format = "fish %c frog";