--- /dev/null
+! { dg-do compile }
+!
+! PR fortran/50898
+! A symbol was freed prematurely during resolution,
+! despite remaining reachable
+!
+! Original testcase from <shaojuncycle@gmail.com>
+
+MODULE MODULE_pmat2
+
+IMPLICIT NONE
+
+INTERFACE cad1b; MODULE PROCEDURE cad1b; END INTERFACE
+INTERFACE csb1b; MODULE PROCEDURE csb1b; END INTERFACE
+INTERFACE copbt; MODULE PROCEDURE copbt; END INTERFACE
+INTERFACE conbt; MODULE PROCEDURE conbt; END INTERFACE
+INTERFACE copmb; MODULE PROCEDURE copmb; END INTERFACE
+INTERFACE conmb; MODULE PROCEDURE conmb; END INTERFACE
+INTERFACE copbm; MODULE PROCEDURE copbm; END INTERFACE
+INTERFACE conbm; MODULE PROCEDURE conbm; END INTERFACE
+INTERFACE mulvb; MODULE PROCEDURE mulvb; END INTERFACE
+INTERFACE madvb; MODULE PROCEDURE madvb; END INTERFACE
+INTERFACE msbvb; MODULE PROCEDURE msbvb; END INTERFACE
+INTERFACE mulxb; MODULE PROCEDURE mulxb; END INTERFACE
+INTERFACE madxb; MODULE PROCEDURE madxb; END INTERFACE
+INTERFACE msbxb; MODULE PROCEDURE msbxb; END INTERFACE
+
+integer, parameter :: i_kind=4
+integer, parameter :: r_kind=4
+real(r_kind), parameter :: zero=0.0
+real(r_kind), parameter :: one=1.0
+real(r_kind), parameter :: two=2.0
+
+CONTAINS
+
+SUBROUTINE cad1b(a,m1,mah1,mah2,mirror2)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1,mah1,mah2,mirror2
+REAL(r_kind), INTENT(INOUT) :: a(0:m1-1,-mah1:mah2)
+RETURN
+ENTRY csb1b(a,m1,mah1,mah2,mirror2)
+END SUBROUTINE cad1b
+
+SUBROUTINE copbt(a,b,m1,m2,mah1,mah2)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2
+REAL(r_kind), INTENT(IN ) :: a(m1,-mah1:mah2)
+REAL(r_kind), INTENT( OUT) :: b(m2,-mah2:mah1)
+RETURN
+ENTRY conbt(a,b,m1,m2,mah1,mah2)
+END SUBROUTINE copbt
+
+SUBROUTINE copmb(afull,aband,m1,m2,mah1,mah2)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2
+REAL(r_kind), DIMENSION(m1,m2), INTENT(IN ) :: afull
+REAL(r_kind), DIMENSION(m1,-mah1:mah2),INTENT( OUT) :: aband
+RETURN
+ENTRY conmb(afull,aband,m1,m2,mah1,mah2)
+END SUBROUTINE copmb
+
+SUBROUTINE copbm(aband,afull,m1,m2,mah1,mah2)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2
+REAL(r_kind), DIMENSION(m1,-mah1:mah2),INTENT(IN ) :: aband
+REAL(r_kind), DIMENSION(m1,m2), INTENT( OUT) :: afull
+RETURN
+ENTRY conbm(aband,afull,m1,m2,mah1,mah2)
+END SUBROUTINE copbm
+
+SUBROUTINE mulbb(a,b,c,m1,m2,mah1,mah2,mbh1,mbh2,mch1,mch2)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2, mbh1, mbh2, mch1, mch2
+REAL(r_kind), INTENT(IN ) :: a(m1,-mah1:mah2), b(m2,-mbh1:mbh2)
+REAL(r_kind), INTENT(INOUT) :: c(m1,-mch1:mch2)
+INTEGER(i_kind) :: nch1, nch2, j, k, jpk, i1,i2
+c=zero
+ENTRY madbb(a,b,c,m1,m2,mah1,mah2,mbh1,mbh2,mch1,mch2)
+nch1=mah1+mbh1; nch2=mah2+mbh2
+IF(nch1 /= mch1 .OR. nch2 /= mch2)STOP 'In MULBB, dimensions inconsistent'
+DO j=-mah1,mah2
+ DO k=-mbh1,mbh2; jpk=j+k; i1=MAX(1,1-j); i2=MIN(m1,m2-j)
+ c(i1:i2,jpk)=c(i1:i2,jpk)+a(i1:i2,j)*b(j+i1:j+i2,k)
+ ENDDO
+ENDDO
+END SUBROUTINE mulbb
+
+SUBROUTINE MULVB(v1,a,v2, m1,m2,mah1,mah2)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2
+REAL(r_kind), INTENT(IN ) :: v1(m1), a(m1,-mah1:mah2)
+REAL(r_kind), INTENT( OUT) :: v2(m2)
+INTEGER(i_kind) :: j, i1,i2
+v2=zero
+ENTRY madvb(v1,a,v2, m1,m2,mah1,mah2)
+DO j=-mah1,mah2; i1=MAX(1,1-j); i2=MIN(m1,m2-j)
+ v2(j+i1:j+i2)=v2(j+i1:j+i2)+v1(i1:i2)*a(i1:i2,j)
+ENDDO
+RETURN
+ENTRY msbvb(v1,a,v2, m1,m2,mah1,mah2)
+DO j=-mah1,mah2; i1=MAX(1,1-j); i2=MIN(m1,m2-j)
+ v2(j+i1:j+i2)=v2(j+i1:j+i2)-v1(i1:i2)*a(i1:i2,j)
+ENDDO
+END SUBROUTINE mulvb
+
+SUBROUTINE mulxb(v1,a,v2, m1,m2,mah1,mah2,my)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2, my
+REAL(r_kind), INTENT(IN ) :: v1(m1,my), a(m1,-mah1:mah2)
+REAL(r_kind), INTENT( OUT) :: v2(m2,my)
+INTEGER(i_kind) :: i,j
+v2=zero
+ENTRY madxb(v1,a,v2, m1,m2,mah1,mah2,my)
+DO j=-mah1,mah2
+ DO i=MAX(1,1-j),MIN(m1,m2-j); v2(j+i,:)=v2(j+i,:)+v1(i,:)*a(i,j); ENDDO
+ENDDO
+RETURN
+ENTRY msbxb(v1,a,v2, m1,m2,mah1,mah2,my)
+DO j=-mah1,mah2
+ DO i=MAX(1,1-j),MIN(m1,m2-j); v2(j+i,:)=v2(j+i,:)-v1(i,:)*a(i,j); ENDDO
+ENDDO
+END SUBROUTINE mulxb
+
+SUBROUTINE mulyb(v1,a,v2, m1,m2,mah1,mah2,mx)
+implicit none
+INTEGER(i_kind), INTENT(IN ) :: m1, m2, mah1, mah2, mx
+REAL(r_kind), INTENT(IN ) :: v1(mx,m1), a(m1,-mah1:mah2)
+REAL(r_kind), INTENT( OUT) :: v2(mx,m2)
+INTEGER(i_kind) :: i,j
+v2=zero
+ENTRY madyb(v1,a,v2, m1,m2,mah1,mah2,mx)
+DO j=-mah1,mah2
+ DO i=MAX(1,1-j),MIN(m1,m2-j)
+ v2(:,j+i)=v2(:,j+i)+v1(:,i)*a(i,j)
+ ENDDO
+ENDDO
+RETURN
+ENTRY msbyb(v1,a,v2, m1,m2,mah1,mah2,mx)
+ DO j=-mah1,mah2
+ DO i=MAX(1,1-j),MIN(m1,m2-j)
+ v2(:,j+i)=v2(:,j+i)-v1(:,i)*a(i,j)
+ ENDDO
+ ENDDO
+RETURN
+END SUBROUTINE mulyb
+
+END MODULE MODULE_pmat2
+