[PATCH] Makefile: abort on shells that do not support ${parameter%word} expansion

From: Brandon Casey <redacted>

Add an entry to the please_set_SHELL_PATH_to_a_more_modern_shell target
which tests whether the shell supports ${parameter%word} expansion.  I
assume this one test is enough to indicate whether the shell supports the
entire family of prefix and suffix removal syntax:

   ${parameter%word}
   ${parameter%%word}
   ${parameter#word}
   ${parameter##word}

FreeBSD, for one, has a /bin/sh that, apparently, supports $() notation but
not the above prefix/suffix removal notation.
---

On 09/05/2011 02:09 AM, Junio C Hamano wrote:

Naohiro Aota [off-list ref] writes:

quoted

Variable expansions like "${foo#bar}" or "${foo%bar}" doesn't work on
shells like FreeBSD sh and they made the test to fail.

Sorry, I do appreciate the effort, but a patch like this takes us in the
wrong direction.

While we do not allow blatant bashisms like ${parameter:offset:length}
(substring expansion), ${parameter/pattern/string} (pattern substitution),
"local" variables, "function" noiseword, and shell arrays in our shell
scripts, the two kinds of substitution you quoted above are purely POSIX,
and our coding guideline does allow them to be used in the scripts.

Perhaps we should add a test for this shell feature.

-Brandon

 Makefile |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index 8d6d451..46d9c5d 100644
--- a/Makefile
+++ b/Makefile

@@ -1738,6 +1738,7 @@ endif
 
 please_set_SHELL_PATH_to_a_more_modern_shell:
 	@$$(:)
+	@foo=bar_suffix && test bar = "$${foo%_*}"
 
 shell_compatibility_test: please_set_SHELL_PATH_to_a_more_modern_shell
 

-- 
1.7.6.1