git-wrapper: fix interpolation with short values

To be precise: when the value of the environment variable is shorter than its name, we have to move the remaining bytes *after* expanding the environment variable: we would look for the wrong name otherwise. When the value is longer than the name, we still need to move the bytes out of the way first, to avoid overwriting them with the interpolated text. This fixes git-for-windows#509 Signed-off-by: Johannes Schindelin <[email protected]>
dscho · Nov 7, 2015 · 15fc2c1 · 15fc2c1
1 parent 9e45a79
commit 15fc2c1
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/compat/win32/git-wrapper.c b/compat/win32/git-wrapper.c
@@ -269,8 +269,10 @@ static LPWSTR expand_variables(LPWSTR buffer, size_t alloc)
 		if (delta > 0)
 			memmove(atat2 + delta, atat2, move_len);
 		len += delta;
-		save = atat[env_len - 1];
+		save = atat[env_len - 1 + (delta < 0 ? -delta : 0)];
 		GetEnvironmentVariable(atat + 2, atat, env_len);
+		if (delta < 0)
+			memmove(atat2 + delta, atat2, move_len);
 		atat[env_len - 1] = save;
 	}