Wrap single lines of code; horizontally scroll multi-line code blocks

CHANGELOG

@@ -95,6 +95,7 @@ v 8.11.0 (unreleased)
   - Sensible state specific default sort order for issues and merge requests !5453 (tomb0y)
   - Fix bug where destroying a namespace would not always destroy projects
   - Fix RequestProfiler::Middleware error when code is reloaded in development
+  - Allow horizontal scrolling of code blocks in issue body
   - Catch what warden might throw when profiling requests to re-throw it
   - Avoid commit lookup on diff_helper passing existing local variable to the helper method
   - Add description to new_issue email and new_merge_request_email in text/plain content type. !5663 (dixpac)

app/assets/stylesheets/framework/typography.scss

@@ -14,12 +14,20 @@
     margin-top: 0;
   }
 
+  // Single code lines should wrap
   code {
     font-family: $monospace_font;
-    white-space: pre;
+    white-space: pre-wrap;
     word-wrap: normal;
   }
 
+  // Multi-line code blocks should scroll horizontally
+  pre {
+    code {
+      white-space: pre;
+    }
+  }
+
   kbd {
     display: inline-block;
     padding: 3px 5px;

app/assets/stylesheets/pages/detail_page.scss

@@ -36,9 +36,17 @@
   }
 
   .wiki {
+    // Single lines of code should wrap
     code {
       white-space: pre-wrap;
       word-break: keep-all;
     }
+
+    // Code blocks should scroll horizontally
+    pre {
+      code {
+        white-space: pre;
+      }
+    }
   }
 }