refactor ~ change repair of 'fix cargo clippy complaints (fatal/sam…

…e if clause)'

.# [why]

The initial refactoring/repair led to comments within if conditions which is
objectionable to some of the devs. So, this changes the refactor to completely split
the if clauses into separate if statements (with corresponding commentary).

Note: this refactor is "less mechanical" and does increase the risk of changing the
actual effect of the code. But the change is small and the tests are passing.

src/fmt/parasplit.rs

@@ -165,19 +165,23 @@ impl<'a> Iterator for FileLines<'a> {
             return Some(Line::NoFormatLine("".to_owned(), true));
         }
 
+        let (pmatch, poffset) = self.match_prefix(&n[..]);
+
         // if this line does not match the prefix,
         // emit the line unprocessed and iterate again
-        let (pmatch, poffset) = self.match_prefix(&n[..]);
-        if !pmatch
-            ||
-            // if the line matches the prefix, but is blank after,
-            // don't allow lines to be combined through it (that is,
-            // treat it like a blank line, except that since it's
-            // not truly blank we will not allow mail headers on the
-            // following line)
-            n[poffset + self.opts.prefix.len()..]
-            .chars()
-            .all(char::is_whitespace)
+        if !pmatch {
+            return Some(Line::NoFormatLine(n, false));
+        }
+
+        // if the line matches the prefix, but is blank after,
+        // don't allow lines to be combined through it (that is,
+        // treat it like a blank line, except that since it's
+        // not truly blank we will not allow mail headers on the
+        // following line)
+        if pmatch
+            && n[poffset + self.opts.prefix.len()..]
+                .chars()
+                .all(char::is_whitespace)
         {
             return Some(Line::NoFormatLine(n, false));
         }
@@ -360,21 +364,26 @@ impl<'a> Iterator for ParagraphStream<'a> {
                     }
                 } else if !second_done {
                     // now we have enough info to handle crown margin and tagged mode
-                    if
+
                     // in both crown and tagged modes we require that prefix_len is the same
-                    prefix_len != fl.prefix_len || pfxind_end != fl.pfxind_end
-                        ||
-                        // in tagged mode, indent has to be *different* on following lines
-                        self.opts.tagged && indent_len - 4 == fl.indent_len && indent_end == fl.indent_end
+                    if prefix_len != fl.prefix_len || pfxind_end != fl.pfxind_end {
+                        break;
+                    }
+
+                    // in tagged mode, indent has to be *different* on following lines
+                    if self.opts.tagged
+                        && indent_len - 4 == fl.indent_len
+                        && indent_end == fl.indent_end
                     {
                         break;
-                    } else {
-                        // this is part of the same paragraph, get the indent info from this line
-                        indent_str.clear();
-                        indent_str.push_str(&fl.line[..fl.indent_end]);
-                        indent_len = fl.indent_len;
-                        indent_end = fl.indent_end;
                     }
+
+                    // this is part of the same paragraph, get the indent info from this line
+                    indent_str.clear();
+                    indent_str.push_str(&fl.line[..fl.indent_end]);
+                    indent_len = fl.indent_len;
+                    indent_end = fl.indent_end;
+
                     second_done = true;
                 } else {
                     // detect mismatch