From 7eb4a755b91c11dccc6f6ebacf6925aea643da9c Mon Sep 17 00:00:00 2001
From: Geoff Hutchison <geoff.hutchison@gmail.com>
Date: Fri, 15 Nov 2024 13:10:14 -0500
Subject: [PATCH] Handle upper-case [ATOMS] line in Molden files from Cfour
 https://discuss.avogadro.cc/t/atoms-in-caps-in-molden-file-does-not-read-the-atoms/6465

Signed-off-by: Geoff Hutchison <geoff.hutchison@gmail.com>
---
 avogadro/core/utilities.h     | 20 +++++++++++++++-----
 avogadro/quantumio/molden.cpp |  2 +-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/avogadro/core/utilities.h b/avogadro/core/utilities.h
index e459b592f5..391d651fea 100644
--- a/avogadro/core/utilities.h
+++ b/avogadro/core/utilities.h
@@ -40,10 +40,20 @@ inline std::vector<std::string> split(const std::string& string, char delimiter,
  * @param search String that will be searched for.
  * @return True if the string contains search, false otherwise.
  */
-inline bool contains(const std::string& input, const std::string& search)
+inline bool contains(const std::string& input, const std::string& search,
+                     bool caseSensitive = true)
 {
-  size_t found = input.find(search);
-  return found != std::string::npos;
+  if (caseSensitive) {
+    return input.find(search) != std::string::npos;
+  } else {
+    std::string inputLower = input;
+    std::string searchLower = search;
+    std::transform(inputLower.begin(), inputLower.end(), inputLower.begin(),
+                   ::tolower);
+    std::transform(searchLower.begin(), searchLower.end(), searchLower.begin(),
+                   ::tolower);
+    return inputLower.find(searchLower) != std::string::npos;
+  }
 }
 
 /**
@@ -98,7 +108,7 @@ T lexicalCast(const std::string& inputString, bool& ok)
   return value;
 }
 
-} // end Core namespace
-} // end Avogadro namespace
+} // namespace Core
+} // namespace Avogadro
 
 #endif // AVOGADRO_CORE_UTILITIES_H
diff --git a/avogadro/quantumio/molden.cpp b/avogadro/quantumio/molden.cpp
index f0ce43461c..13b2720d26 100644
--- a/avogadro/quantumio/molden.cpp
+++ b/avogadro/quantumio/molden.cpp
@@ -97,7 +97,7 @@ void MoldenFile::processLine(std::istream& in)
   // Molden file format uses sections, each starts with a header line of the
   // form [Atoms], and the beginning of a new section denotes the end of the
   // last.
-  if (Core::contains(line, "[Atoms]")) {
+  if (Core::contains(line, "[Atoms]") || Core::contains(line, "[ATOMS]")) {
     if (list.size() > 1 && Core::contains(list[1], "AU"))
       m_coordFactor = BOHR_TO_ANGSTROM_D;
     m_mode = Atoms;