From 96abdb5f78052b77ec29b1c2042bdfcffd21b666 Mon Sep 17 00:00:00 2001
From: Jack Rann <jack.rann@gmail.com>
Date: Sat, 28 Sep 2024 16:59:06 -0700
Subject: [PATCH] Handle Python execution via execvp().  New test to validate
 single quote handling in argument.

---
 src/engines/python-engine.cc | 25 +++++++++++++++++--------
 tests/python/echo.py         | 10 ++++++++++
 tests/tools/test_python.py   | 11 +++++++++++
 3 files changed, 38 insertions(+), 8 deletions(-)
 create mode 100755 tests/python/echo.py

diff --git a/src/engines/python-engine.cc b/src/engines/python-engine.cc
index 3aa5c3e4..1575c973 100644
--- a/src/engines/python-engine.cc
+++ b/src/engines/python-engine.cc
@@ -96,16 +96,25 @@ class PythonEngine : public ScriptEngineBase
 			const char **argv = conf.getArgv();
 			unsigned int argc = conf.getArgc();
 
-			std::string s = fmt("%s %s ", command.c_str(), kcov_python_path.c_str());
-			for (unsigned int i = 0; i < argc; i++)
-				s += "'" + std::string(argv[i]) + "' ";
-
-			int res;
+			// Make a copy of the vector, with python + helper script first
+			char **vec;
+			int argcStart = 2;
+			vec = (char **) xmalloc(sizeof(char *) * (argc + 3));
+			vec[0] = xstrdup(command.c_str());
+			vec[1] = xstrdup(kcov_python_path.c_str());
+
+			for (unsigned i = 0; i < argc; i++)
+				vec[argcStart + i] = xstrdup(argv[i]);
+
+			/* Execute the script */
+			if (execvp(vec[0], vec))
+			{
+				perror("Failed to execute python helper");
 
-			res = system(s.c_str());
-			panic_if(res < 0, "Can't execute python helper");
+				free(vec);
 
-			exit(WEXITSTATUS(res));
+				return false;
+			}
 		}
 		else if (m_child < 0)
 		{
diff --git a/tests/python/echo.py b/tests/python/echo.py
new file mode 100755
index 00000000..b702ac69
--- /dev/null
+++ b/tests/python/echo.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python3
+
+import sys
+
+def main():
+    print('echo:', sys.argv)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/tests/tools/test_python.py b/tests/tools/test_python.py
index ca379f1c..de7b511b 100644
--- a/tests/tools/test_python.py
+++ b/tests/tools/test_python.py
@@ -190,3 +190,14 @@ def runTest(self):
         dom = cobertura.parseFile(self.outbase + "/kcov/main/cobertura.xml")
         assert cobertura.hitsPerLine(dom, "second.py", 57) == 1
         assert cobertura.hitsPerLine(dom, "second.py", 61) == 1
+
+
+class python_single_quote_arg(libkcov.TestCase):
+    def runTest(self):
+        rv, o = self.do(
+            self.kcov + " " + self.outbase + "/kcov " + self.sources + "/tests/python/echo.py 1 two a'b"
+        )
+
+        assert b"1" in o
+        assert b"two" in o
+        assert b"a'b" in o