Have commit-msg report commit failure

[gnu-emacs] / build-aux / git-hooks / commit-msg

diff --git a/build-aux/git-hooks/commit-msg b/build-aux/git-hooks/commit-msg
index d2a0c59dace577996e2747df6c886e07e9aad037..6721d53a582363930c05ab30ecd4ad4edd9f2021 100755 (executable)
--- a/build-aux/git-hooks/commit-msg
+++ b/build-aux/git-hooks/commit-msg
@@ -1,7 +1,7 @@
 #!/bin/sh
 # Check the format of GNU Emacs change log entries.
 
-# Copyright 2014 Free Software Foundation, Inc.
+# Copyright 2014-2015 Free Software Foundation, Inc.
 
 # This file is part of GNU Emacs.
 
@@ -46,6 +46,20 @@ fi
 
 # Check the log entry.
 exec $awk '
+  BEGIN {
+    if (" " ~ /[[:space:]]/) {
+      space = "[[:space:]]"
+      non_space = "[^[:space:]]"
+      non_print = "[^[:print:]]"
+    } else {
+      # mawk 1.3.3 does not support POSIX bracket expressions.
+      # Approximate them as best we can.
+      space = "[ \f\n\r\t\v]"
+      non_space = "[^ \f\n\r\t\v]"
+      non_print = "[\1-\37\177]"
+    }
+  }
+
   /^#/ { next }
 
   !/^.*$/ {
@@ -53,7 +67,7 @@ exec $awk '
     status = 1
   }
 
-  nlines == 0 && !/[^[:space:]]/ { next }
+  nlines == 0 && $0 !~ non_space { next }
 
   { nlines++ }
 
@@ -62,19 +76,28 @@ exec $awk '
     if (! sub(/^fixup! /, ""))
       sub(/^squash! /, "")
 
-    if (/^[[:space:]]/) {
+    if ($0 ~ "^" space) {
       print "White space at start of commit message'\''s first line"
       status = 1
     }
   }
 
-  nlines == 2 && /[^[:space:]]/ {
+  nlines == 2 && $0 ~ non_space {
     print "Nonempty second line in commit message"
     status = 1
   }
 
-  72 < length && /[[:space:]]/ {
-    print "Line longer than 72 characters in commit message"
+  {
+    # Expand tabs to spaces for length calculations etc.
+    while (match($0, /\t/)) {
+      before_tab = substr($0, 1, RSTART - 1)
+      after_tab = substr($0, RSTART + 1)
+      $0 = sprintf("%s%*s%s", before_tab, 8 - (RSTART - 1) % 8, "", after_tab)
+    }
+  }
+
+  78 < length && $0 ~ space {
+    print "Line longer than 78 characters in commit message"
     status = 1
   }
 
@@ -88,13 +111,8 @@ exec $awk '
     status = 1
   }
 
-  /[^[:print:]]/ {
-    if (gsub(/\t/, "")) {
-      print "Tab in commit message; please use spaces instead"
-    }
-    if (/[^[:print:]]/) {
-      print "Unprintable character in commit message"
-    }
+  $0 ~ non_print {
+    print "Unprintable character in commit message"
     status = 1
   }
 
@@ -103,6 +121,9 @@ exec $awk '
       print "Empty commit message"
       status = 1
     }
+    if (status != 0) {
+      print "Commit aborted; please see the file 'CONTRIBUTE'"
+    }
     exit status
   }
 ' <"$1"