From aaa9392f8b1e4a2af63e46dfd64a2184a39d338b Mon Sep 17 00:00:00 2001
From: Tagir Valeev <tagir.valeev@jetbrains.com>
Date: Mon, 25 Jul 2022 16:11:56 +0200
Subject: [PATCH] [java-inspections] IDEA-298388 "Java | Code style issues |
 Non-terminal use of '\s' escape sequence" false positive

GitOrigin-RevId: 3e7989a3bf971e7b6be613abee893cbe334dde31
---
 .../escapedSpace/beforeSlashSlash.java        |  8 +++++
 .../ig/style/EscapedSpaceInspection.java      | 33 ++++++++++++++-----
 2 files changed, 33 insertions(+), 8 deletions(-)
 create mode 100644 java/java-tests/testData/codeInspection/escapedSpace/beforeSlashSlash.java

diff --git a/java/java-tests/testData/codeInspection/escapedSpace/beforeSlashSlash.java b/java/java-tests/testData/codeInspection/escapedSpace/beforeSlashSlash.java
new file mode 100644
index 000000000000..5296ee328be6
--- /dev/null
+++ b/java/java-tests/testData/codeInspection/escapedSpace/beforeSlashSlash.java
@@ -0,0 +1,8 @@
+// "Replace with a space" "false"
+class X {
+  void test(String str) {
+    if (str.matches("\\<caret>s+")) {
+
+    }
+  }
+}
\ No newline at end of file
diff --git a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/style/EscapedSpaceInspection.java b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/style/EscapedSpaceInspection.java
index 8f7780a9092a..38a334131c04 100644
--- a/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/style/EscapedSpaceInspection.java
+++ b/plugins/InspectionGadgets/InspectionGadgetsAnalysis/src/com/siyeh/ig/style/EscapedSpaceInspection.java
@@ -22,16 +22,33 @@ public class EscapedSpaceInspection extends AbstractBaseJavaLocalInspectionTool
         if (!TypeUtils.isJavaLangString(type)) return;
         boolean block = literal.isTextBlock();
         String text = literal.getText();
-        int pos = 0;
+        int pos = 1;
         while (true) {
-          pos = text.indexOf("\\s", pos + 1);
-          if (pos == -1) return;
-          if (pos > 2 && text.startsWith("\\s", pos - 2)) continue;
-          if (text.startsWith("\\s", pos + 2)) continue;
-          if (block && (pos + 2 == text.length() || text.charAt(pos + 2) == '\n')) continue;
-          holder.registerProblem(literal, TextRange.create(pos, pos+2),
+          pos = text.indexOf('\\', pos);
+          if (pos == -1 || pos == text.length() - 1) return;
+          char next = text.charAt(pos + 1);
+          if (next == 'u') {
+            // unicode escape
+            pos += 6;
+            continue;
+          }
+          pos += 2;
+          if (next >= '0' && next <= '9') {
+            // octal escape
+            if (pos < text.length() && text.charAt(pos) >= '0' && text.charAt(pos) <= '9') pos++;
+            if (pos < text.length() && text.charAt(pos) >= '0' && text.charAt(pos) <= '9') pos++;
+            continue;
+          }
+          if (next != 's') {
+            // other escapes
+            continue;
+          }
+          if (pos > 4 && text.startsWith("\\s", pos - 4)) continue;
+          if (text.startsWith("\\s", pos)) continue;
+          if (block && (pos == text.length() || text.charAt(pos) == '\n')) continue;
+          holder.registerProblem(literal, TextRange.create(pos - 2, pos),
                                  InspectionGadgetsBundle.message("inspection.use.of.slash.s.message"),
-                                 new ReplaceWithSpaceFix(pos));
+                                 new ReplaceWithSpaceFix(pos - 2));
         }
       }
     };