Fix #381 (When there are header files with the same name, the correct file cannot be found)

simplecpp.cpp

@@ -3278,6 +3278,13 @@ static std::string getFileIdPath(const std::map<std::string, simplecpp::TokenLis
         if (!match.empty()) {
             return match;
         }
+        // if the file exists but hasn't been loaded yet then we need to stop searching here or we could get a false match
+        std::ifstream f;
+        openHeader(f, relativeOrAbsoluteFilename);
+        if (f.is_open()) {
+            f.close();
+            return "";
+        }
     } else if (filedata.find(header) != filedata.end()) {
         return header;// system header that its file is already in the filedata - return that as is
     }

test.cpp

@@ -2990,6 +2990,43 @@ static void fuzz_crash()
     }
 }
 
+static void same_name()
+{
+    const char code[] = "#include <header_a.h>\n"
+                        "#include <header_b.h>\n"
+                        "TEST\n";
+
+    simplecpp::DUI dui;
+    dui.includePaths.push_back("./testsuite/path-tests/include_a");
+    dui.includePaths.push_back("./testsuite/path-tests/include_b");
+
+    ASSERT_EQUALS("\n\nOK", preprocess(code, dui));
+}
+
+static void file_id()
+{
+    const char code[] = "#include \"once.h\"\n"
+                        "#include \"Once.h\"\n"
+
+                        "#include <once.h>\n"
+                        "#include <Once.h>\n"
+
+                        "#include \"../path-tests/once.h\"\n"
+                        "#include \"../path-tests/Once.h\"\n"
+                        "#include \"../Path-Tests/once.h\"\n"
+                        "#include \"../Path-Tests/Once.h\"\n"
+
+                        "#include \"include_a/../once.h\"\n"
+                        "#include \"include_a/../Once.h\"\n"
+                        "#include \"include_A/../once.h\"\n"
+                        "#include \"include_A/../Once.h\"\n";
+
+    simplecpp::DUI dui;
+    dui.includePaths.push_back("./testsuite/path-tests");
+
+    ASSERT_EQUALS("\n#line 2 \"testsuite/path-tests/once.h\"\nONCE", preprocess(code, dui));
+}
+
 int main(int argc, char **argv)
 {
     TEST_CASE(backslash);
@@ -3212,6 +3249,10 @@ int main(int argc, char **argv)
 
     TEST_CASE(warning);
 
+    // path resolution
+    TEST_CASE(same_name);
+    TEST_CASE(file_id);
+
     // utility functions.
     TEST_CASE(simplifyPath);
     TEST_CASE(simplifyPath_cppcheck);

testsuite/path-tests/include_a/header_a.h

@@ -0,0 +1 @@
+#include "same_name.h"

testsuite/path-tests/include_a/same_name.h

@@ -0,0 +1 @@
+#define TEST E

testsuite/path-tests/include_b/header_b.h

@@ -0,0 +1 @@
+#include "same_name.h"

testsuite/path-tests/include_b/same_name.h

@@ -0,0 +1 @@
+#define TEST OK

testsuite/path-tests/once.h

@@ -0,0 +1,2 @@
+#pragma once
+ONCE