From 09d182d9dfde5d68c4481edfa1bb77453b111380 Mon Sep 17 00:00:00 2001
From: Joshua Watt <JPEWhacker@gmail.com>
Date: Mon, 31 Jul 2023 13:15:27 -0600
Subject: [PATCH] Do nothing if interpreter has not changed

If there is not change to the interpreter, don't make any modifications
to the file. This is more efficient than requiring programs to check
before changing, and also prevents thrashing of the ELF file, since
changing the interpreter repeatedly will keep growing the ELF file each
time, even if it's the same value.

This is particularly helpful where the same binary is symlinked or
hardlinked with multiple names and has patchelf run on it.
---
 src/patchelf.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/patchelf.cc b/src/patchelf.cc
index 82b4b46c..bc400268 100644
--- a/src/patchelf.cc
+++ b/src/patchelf.cc
@@ -1454,6 +1454,10 @@ void ElfFile<ElfFileParamNames>::modifySoname(sonameMode op, const std::string &
 template<ElfFileParams>
 void ElfFile<ElfFileParamNames>::setInterpreter(const std::string & newInterpreter)
 {
+    if (getInterpreter() == newInterpreter) {
+        return;
+    }
+
     std::string & section = replaceSection(".interp", newInterpreter.size() + 1);
     setSubstr(section, 0, newInterpreter + '\0');
     changed = true;