diff --git a/Documentation/pretty-formats.txt b/Documentation/pretty-formats.txt
index 582454a4f7..4a83796250 100644
--- a/Documentation/pretty-formats.txt
+++ b/Documentation/pretty-formats.txt
@@ -144,7 +144,9 @@ ifndef::git-rev-list[]
 endif::git-rev-list[]
 - '%GR': contents of the commits signature (blank when unsigned)
 - '%G+': "Y" if the commit is signed, "N" otherwise
-- '%GG': raw verification message from GPG for a signed commit
+- '%GG': raw verification message from GPG for a signed commit.
+  This and all the other %G* placeholders, other than %GR, %G+, and
+  %G?, return blank if GPG cannot be run.
 - '%G?': show "G" for a good (valid) signature,
   "B" for a bad signature,
   "U" for a good signature with unknown validity,
@@ -152,7 +154,7 @@ endif::git-rev-list[]
   "Y" for a good signature made by an expired key,
   "R" for a good signature made by a revoked key,
   "E" if the signature cannot be checked (e.g. missing key)
-  and "N" for no signature
+  and "N" for no signature (e.g. unsigned, or GPG cannot be run)
 - '%GS': show the name of the signer for a signed commit
 - '%GK': show the key used to sign a signed commit
 - '%GF': show the fingerprint of the key used to sign a signed commit
diff --git a/t/t7510-signed-commit.sh b/t/t7510-signed-commit.sh
index aff6b1eb3a..d65425eddc 100755
--- a/t/t7510-signed-commit.sh
+++ b/t/t7510-signed-commit.sh
@@ -170,6 +170,48 @@ test_expect_success GPG 'amending already signed commit' '
 	! grep "BAD signature from" actual
 '
 
+test_expect_success GPG 'show custom format fields for signed commit if gpg is missing' '
+	cat >expect <<-\EOF &&
+	N
+
+
+
+
+	Y
+	EOF
+	test_config gpg.program this-is-not-a-program &&
+	git log -n1 --format="%G?%n%GK%n%GS%n%GF%n%GP%n%G+" sixth-signed >actual 2>/dev/null &&
+	test_cmp expect actual
+'
+
+test_expect_success GPG 'show custom format fields for unsigned commit if gpg is missing' '
+	cat >expect <<-\EOF &&
+	N
+
+
+
+
+	N
+	EOF
+	test_config gpg.program this-is-not-a-program &&
+	git log -n1 --format="%G?%n%GK%n%GS%n%GF%n%GP%n%G+" seventh-unsigned >actual 2>/dev/null &&
+	test_cmp expect actual
+'
+
+test_expect_success GPG 'show error for custom format fields on signed commit if gpg is missing' '
+	test_config gpg.program this-is-not-a-program &&
+	git log -n1 --format="%G?%n%GK%n%GS%n%GF%n%GP%n%G+" sixth-signed >/dev/null 2>errors &&
+	test $(wc -l <errors) = 1 &&
+	test_i18ngrep "^error: " errors &&
+	grep this-is-not-a-program errors
+'
+
+test_expect_success GPG 'do not run gpg at all for unsigned commit' '
+	test_config gpg.program this-is-not-a-program &&
+	git log -n1 --format="%G?%n%GK%n%GS%n%GF%n%GP%n%G+" seventh-unsigned >/dev/null 2>errors &&
+	test_must_be_empty errors
+'
+
 test_expect_success GPG 'show good signature with custom format' '
 	cat >expect <<-\EOF &&
 	G
@@ -240,6 +282,14 @@ test_expect_success GPG 'show lack of raw signature with custom format' '
 	test_must_be_empty actual
 '
 
+test_expect_success GPG 'show lack of raw signature with custom format without running GPG' '
+	echo N > expected &&
+	test_config gpg.program this-is-not-a-program &&
+	git log -1 --format="%G+%GR" seventh-unsigned >actual 2>errors &&
+	test_cmp expected actual &&
+	test_must_be_empty errors
+'
+
 test_expect_success GPG 'show raw signature with custom format' '
 	git log -1 --format=format:"%GR" sixth-signed >output &&
 	cat output &&
@@ -250,6 +300,51 @@ test_expect_success GPG 'show raw signature with custom format' '
 	tail -n1 output | grep -q "^---*END PGP SIGNATURE---*$"
 '
 
+test_expect_success GPG 'show raw signature with custom format without running GPG' '
+	test_config gpg.program this-is-not-a-program &&
+	git log -1 --format=format:"%GR" sixth-signed >rawsig 2>errors &&
+	cat rawsig &&
+	head -n1 rawsig | grep -q "^---*BEGIN PGP SIGNATURE---*$" &&
+	sed 1d rawsig | grep -q "^$" &&
+	sed "1,/^$/d" rawsig | grep -q "^[a-zA-Z0-9+/][a-zA-Z0-9+/=]*$" &&
+	tail -n2 rawsig | head -n1 | grep -q "^=[a-zA-Z0-9+/][a-zA-Z0-9+/=]*$" &&
+	tail -n1 rawsig | grep -q "^---*END PGP SIGNATURE---*$" &&
+	test_must_be_empty errors
+'
+
+test_expect_success GPG 'show presence of gpgsig with custom format when gpg is missing without errors' '
+	echo Y > expected &&
+	git log -1 --format=%G+ sixth-signed >output 2>errors &&
+	test_cmp expected output &&
+	test_must_be_empty errors
+'
+
+test_expect_success GPG 'show presence of invalid gpgsig header' '
+	printf gpgsig >gpgsig-header &&
+	tee prank-signature <<-\EOF | sed "s/^/ /" >>gpgsig-header &&
+	this is not a signature but an awful...
+					   888
+					   888
+					   888
+	88888b.  888d888  8888b.  88888b.  888  888
+	888 "88b 888P"       "88b 888 "88b 888 .88P
+	888  888 888     .d888888 888  888 888888K
+	888 d88P 888     888  888 888  888 888 "88b
+	88888P"  888     "Y888888 888  888 888  888
+	888
+	888
+	888
+	EOF
+	git cat-file commit seventh-unsigned >bare-commit-data &&
+	sed "/^committer/r gpgsig-header" bare-commit-data >commit-data &&
+	git hash-object -w -t commit commit-data >commit &&
+	echo Y >expected &&
+	cat prank-signature >>expected &&
+	git log -n1 --format=format:%G+%n%GR $(cat commit) >actual 2>errors &&
+	test_cmp expected actual &&
+	test_must_be_empty errors
+'
+
 test_expect_success GPG 'log.showsignature behaves like --show-signature' '
 	test_config log.showsignature true &&
 	git show initial >actual &&
