Add Coverity defect fix commit checker support

Enable commitcheck.sh to test if a commit message is
in the expected format for a coverity defect fix.

Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Closes #6777

scripts/commitcheck.sh

@@ -15,6 +15,19 @@ function test_url()
     return 0
 }
 
+# test commit body for length
+function test_commit_bodylength()
+{
+    length="72"
+    body=$(git log -n 1 --pretty=%b "$REF" | egrep -m 1 ".{$((length + 1))}")
+    if [ -n "$body" ]; then
+        echo "error: commit message body contains line over ${length} characters"
+        return 1
+    fi
+
+    return 0
+}
+
 # check for a tagged line
 function check_tagged_line()
 {
@@ -29,7 +42,7 @@ function check_tagged_line()
 }
 
 # check for a tagged line and check that the link is valid
-function check_tagged_line_with_url ()
+function check_tagged_line_with_url()
 {
     regex='^\s*'"$1"':\s\K([[:graph:]]+)$'
     foundline=$(git log -n 1 "$REF" | grep -Po "$regex")
@@ -63,9 +76,7 @@ function new_change_commit()
     fi
 
     # ensure that no lines in the body of the commit are over 72 characters
-    body=$(git log -n 1 --pretty=%b "$REF" | egrep -m 1 '.{73}')
+    if ! test_commit_bodylength ; then
-    if [ -n "$body" ]; then
-        echo "error: commit message body contains line over 72 characters"
         error=1
     fi
 
@@ -85,10 +96,12 @@ function is_openzfs_port()
 
 function openzfs_port_commit()
 {
+    error=0
+
     # subject starts with OpenZFS dddd
     subject=$(git log -n 1 --pretty=%s "$REF" | egrep -m 1 '^OpenZFS [[:digit:]]+ - ')
     if [ -z "$subject" ]; then
-        echo "OpenZFS patch ports must have a summary that starts with \"OpenZFS dddd - \""
+        echo "error: OpenZFS patch ports must have a subject line that starts with \"OpenZFS dddd - \""
         error=1
     fi
 
@@ -125,6 +138,54 @@ function openzfs_port_commit()
     return $error
 }
 
+function is_coverity_fix()
+{
+    # subject starts with Fix coverity defects means it's a coverity fix
+    subject=$(git log -n 1 --pretty=%s "$REF" | egrep -m 1 '^Fix coverity defects')
+    if [ -n "$subject" ]; then
+        return 0
+    fi
+
+    return 1
+}
+
+function coverity_fix_commit()
+{
+    error=0
+
+    # subject starts with Fix coverity defects: CID dddd, dddd...
+    subject=$(git log -n 1 --pretty=%s "$REF" |
+        egrep -m 1 'Fix coverity defects: CID [[:digit:]]+(, [[:digit:]]+)*')
+    if [ -z "$subject" ]; then
+        echo "error: Coverity defect fixes must have a subject line that starts with \"Fix coverity defects: CID dddd\""
+        error=1
+    fi
+
+    # need a signed off by
+    if ! check_tagged_line "Signed-off-by" ; then
+        error=1
+    fi
+
+    # test each summary line for the proper format
+    OLDIFS=$IFS
+    IFS=$'\n'
+    for line in $(git log -n 1 --pretty=%b "$REF" | egrep '^CID'); do
+        echo "$line" | egrep '^CID [[:digit:]]+: ([[:graph:]]+|[[:space:]])+ \(([[:upper:]]|\_)+\)' > /dev/null
+        if [[ $? -ne 0 ]]; then
+            echo "error: commit message has an improperly formatted CID defect line"
+            error=1
+        fi
+    done
+    IFS=$OLDIFS
+
+    # ensure that no lines in the body of the commit are over 72 characters
+    if ! test_commit_bodylength; then
+        error=1
+    fi
+
+    return $error
+}
+
 if [ -n "$1" ]; then
     REF="$1"
 fi
@@ -138,6 +199,15 @@ if is_openzfs_port; then
     fi
 fi
 
+# if coverity fix, test against that
+if is_coverity_fix; then
+    if ! coverity_fix_commit; then
+        exit 1
+    else
+        exit 0
+    fi
+fi
+
 # have a normal commit
 if ! new_change_commit ; then
     exit 1