From f401f0be89cf5ca29278cc836cdb50faca4613aa Mon Sep 17 00:00:00 2001
From: Runxi Yu <me@runxiyu.org>
Date: Fri, 07 Mar 2025 15:15:29 +0800
Subject: [PATCH] hooks: Send/process environment variables starting with GIT_

---
 git_hooks_client/git_hooks_client.c | 32 ++++++++++++++++++++++++++++++++
 git_hooks_handle.go                 | 29 +++++++++++++++++++++++++++++

diff --git a/git_hooks_client/git_hooks_client.c b/git_hooks_client/git_hooks_client.c
index fc49d915c8f9db46a760b71659c45a7f3c7c88f4..bdc6dc24f397ed940ba93a1aa008113ab085560c 100644
--- a/git_hooks_client/git_hooks_client.c
+++ b/git_hooks_client/git_hooks_client.c
@@ -154,6 +154,38 @@ 		}
 	}
 
 	/*
+	 * Then send all environment variables that begin with "GIT_"
+	 */
+	extern char **environ;
+	for (char **env = environ; *env != NULL; env++) {
+		if (strncmp(*env, "GIT_", 4) == 0) {
+			unsigned long len = strlen(*env) + 1;
+			bytes_sent = send(sock, *env, len, 0);
+			if (bytes_sent == -1) {
+				perror("send env");
+				close(sock);
+				exit(EXIT_FAILURE);
+			} else if ((unsigned long)bytes_sent == len) {
+			} else {
+				dprintf(STDERR_FILENO, "send returned unexpected value on internal socket\n");
+				close(sock);
+				exit(EXIT_FAILURE);
+			}
+		}
+	}
+	bytes_sent = send(sock, "", 1, 0);
+	if (bytes_sent == -1) {
+		perror("send env terminator");
+		close(sock);
+		exit(EXIT_FAILURE);
+	} else if (bytes_sent == 1) {
+	} else {
+		dprintf(STDERR_FILENO, "send returned unexpected value on internal socket\n");
+		close(sock);
+		exit(EXIT_FAILURE);
+	}
+
+	/*
 	 * Now we can start splicing data from stdin to the UNIX domain socket.
 	 * The format is irrelevant and depends on the hook being called. All we
 	 * do is pass it to the socket for it to handle.
diff --git a/git_hooks_handle.go b/git_hooks_handle.go
index 063eb50900fca7b0db2913350b363322af9833fa..69fe0aa6f6aca0f0ba924b194b51b3d5be321f5e 100644
--- a/git_hooks_handle.go
+++ b/git_hooks_handle.go
@@ -108,6 +108,35 @@ 			}
 			args = append(args, arg.String())
 		}
 
+		git_env := make(map[string]string)
+		for {
+			var env_line bytes.Buffer
+			for {
+				b := make([]byte, 1)
+				n, err := conn.Read(b)
+				if err != nil || n != 1 {
+					wf_error(ssh_stderr, "Failed to read environment variable: %v", err)
+					return 1
+				}
+				if b[0] == 0 {
+					break
+				}
+				env_line.WriteByte(b[0])
+			}
+			if env_line.Len() == 0 {
+				break
+			}
+			kv := env_line.String()
+			parts := strings.SplitN(kv, "=", 2)
+			if len(parts) < 2 {
+				wf_error(ssh_stderr, "Invalid environment variable line: %v", kv)
+				return 1
+			}
+			git_env[parts[0]] = parts[1]
+		}
+
+		fmt.Printf("%#v\n", git_env)
+
 		var stdin bytes.Buffer
 		if _, err = io.Copy(&stdin, conn); err != nil {
 			wf_error(conn, "Failed to read to the stdin buffer: %v", err)

-- 
2.48.1