fix: fix addGitBashToEnv and addGitToEnv on Windows

Functional changes:

- Include the mingw directory in the PATH
(this directory contains many of the actual git functions,
such as `git-pull`, `git-push`, and `git-upload-pack`).

- Search `env.ProgramW6432` for Git before `env.ProgramFiles`,
as `ProgramFiles` is not guaranteed to always point to
the x64 Program Files directory.

Technically, we should get the mingw path from `git --exec-path`
(and this is what the GitHub package does), but that would mean
making `git.addGitToEnv(env)` async,
which would have been a much larger PR.

From atom/apm#839

Co-Authored-By: Winston Liu <2766036+50Wliu@users.noreply.github.com>

src/git.ts

@@ -27,22 +27,40 @@ function addPortableGitToEnv(env: Record<string, string | undefined>) {
     if (child.indexOf("PortableGit_") === 0) {
       const cmdPath = path.join(githubPath, child, "cmd")
       const binPath = path.join(githubPath, child, "bin")
+      let corePath = path.join(githubPath, child, "mingw64", "libexec", "git-core")
+      if (!fs.isDirectorySync(corePath)) {
+        corePath = path.join(githubPath, child, "mingw32", "libexec", "git-core")
+      }
+
       if (env.Path) {
-        env.Path += `${path.delimiter}${cmdPath}${path.delimiter}${binPath}`
+        env.Path += `${path.delimiter}${cmdPath}${path.delimiter}${binPath}${path.delimiter}${corePath}`
       } else {
-        env.Path = `${cmdPath}${path.delimiter}${binPath}`
+        env.Path = `${cmdPath}${path.delimiter}${binPath}${path.delimiter}${corePath}`
       }
       break
     }
   }
 }
 
 function addGitBashToEnv(env: Record<string, string | undefined>) {
+  // First, check ProgramW6432, as it will _always_ point to the 64-bit Program Files directory
   let gitPath: string
-  if (env.ProgramFiles) {
-    gitPath = path.join(env.ProgramFiles, "Git")
+  if (env.ProgramW6432) {
+    gitPath = path.join(env.ProgramW6432, "Git")
   }
 
+  // Next, check ProgramFiles - this will point to:
+  // - x64 Program Files when running a 64-bit process on 64-bit Windows
+  // - x86 Program Files when running a 32-bit process on 64-bit Windows
+  // - x86 Program Files when running on 32-bit Windows
+  if (!fs.isDirectorySync(gitPath)) {
+    if (env.ProgramFiles) {
+      gitPath = path.join(env.ProgramFiles, "Git")
+    }
+  }
+
+  // Finally, check ProgramFiles(x86) to see if 32-bit Git was installed on 64-bit Windows
+
   if (!fs.isDirectorySync(gitPath)) {
     if (env["ProgramFiles(x86)"]) {
       gitPath = path.join(env["ProgramFiles(x86)"], "Git")
@@ -55,10 +73,15 @@ function addGitBashToEnv(env: Record<string, string | undefined>) {
 
   const cmdPath = path.join(gitPath, "cmd")
   const binPath = path.join(gitPath, "bin")
+  let corePath = path.join(gitPath, "mingw64", "libexec", "git-core")
+  if (!fs.isDirectorySync(corePath)) {
+    corePath = path.join(gitPath, "mingw32", "libexec", "git-core")
+  }
+
   if (env.Path) {
-    return (env.Path += `${path.delimiter}${cmdPath}${path.delimiter}${binPath}`)
+    return (env.Path += `${path.delimiter}${cmdPath}${path.delimiter}${binPath}${path.delimiter}${corePath}`)
   } else {
-    return (env.Path = `${cmdPath}${path.delimiter}${binPath}`)
+    return (env.Path = `${cmdPath}${path.delimiter}${binPath}${path.delimiter}${corePath}`)
   }
 }