userdiff: extend Bash pattern to cover more shell function forms

The previous function regex required explicit matching of function
bodies using `{`, `(`, `((`, or `[[`, which caused several issues:

- It failed to capture valid functions where `{` was on the next line
  due to line continuation (`\`).
- It did not recognize functions with single  command body, such as
  `x () echo hello`.

Replacing the function body matching logic with `.*$`, ensures
that everything on the function definition line is captured.

Additionally, the word regex is refined to better recognize shell
syntax, including additional parameter expansion operators and
command-line options.

Signed-off-by: Moumita Dhar <dhar61595@gmail.com>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/t/t4034/bash/post b/t/t4034/bash/post
new file mode 100644
index 0000000000..2bbee8936d
--- /dev/null
+++ b/t/t4034/bash/post
@@ -0,0 +1,31 @@
+new_var=10
+x=456
+echo $2
+echo $USERNAME
+${HOMEDIR}
+((a+=b))
+((a*=b))
+((a/=b))
+((a%=b))
+((a|=b))
+((a^=b))
+((a==b))
+((a!=b))
+((a<=b))
+((a>=b))
+$((a<<b))
+$((a>>b))
+$((a&&b))
+$((a||b))
+${a:-b}
+${a:=b}
+${a:+b}
+${a:?b}
+${a##*/}
+${a%%.*}
+${a^^}
+${a,,}
+${!a}
+${a[@]}
+ls -x
+ls --color