Auto merge of rust-lang#12549 - granddaifuku:fix/suspicious_else_formatting-false-positive-when-commented-else, r=Alexendoo

fix: `suspicious_else_formatting` false positive when else is included …

This PR addresses an issue where invalid suggestions are generated for `if-else` formatting if comments contain the keyword `else`.

The root of the problem is identified [here](https://github.com/rust-lang/rust-clippy/blob/95c62ffae9bbce793f68a6f1473e3fc24af19bdd/clippy_lints/src/formatting.rs#L217). Specifically, when a comment contains the word `else`, the lint mistakenly interprets it as part of an `if-else` clause. This misinterpretation leads to an incorrect splitting of the snippet, resulting in erroneous suggestions.

fixes: rust-lang#12497

changelog: [`suspicious_else_formatting`]: Fixes invalid suggestions when comments include word else

Author: bors

clippy_lints/src/formatting.rs

@@ -215,6 +215,7 @@ fn check_else(cx: &EarlyContext<'_>, expr: &Expr) {
         // it’s bad when there is a ‘\n’ after the “else”
         && let Some(else_snippet) = snippet_opt(cx, else_span)
         && let Some((pre_else, post_else)) = else_snippet.split_once("else")
+        && !else_snippet.contains('/')
         && let Some((_, post_else_post_eol)) = post_else.split_once('\n')
     {
         // Allow allman style braces `} \n else \n {`

tests/ui/suspicious_else_formatting.rs

@@ -120,6 +120,34 @@ fn main() {
     /* whelp */
     {
     }
+
+    // #12497 Don't trigger lint as rustfmt wants it
+    if true {
+        println!("true");
+    }
+    /*else if false {
+}*/
+    else {
+        println!("false");
+    }
+
+    if true {
+        println!("true");
+    } // else if false {}
+    else {
+        println!("false");
+    }
+
+    if true {
+        println!("true");
+    } /* if true {
+        println!("true");
+}
+    */
+    else {
+        println!("false");
+    }
+
 }
 
 // #7650 - Don't lint. Proc-macro using bad spans for `if` expressions.