loader: archive main class should fall back to Main-Class attribute if the Start-Class attribute is unavailable

[patrikbeno]

see

spring-boot/spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/archive/Archive.java

Line 50 in cb067ee

public String getMainClass() throws Exception {

[patrikbeno]

#2685

[wilkinsona]

What's your use case for falling back to Main-Class?

[patrikbeno]

Null layout, or pluggable layouts in general, as introduced in #2629.

You may have a layout that does not inject loader and/or does not override archive entry point (Main-Class).
In such case, expected behavior is to leave Main-Class as is.

[snicoll]

Closing in favour of pr #2685